Volunteering Attitude, Mental Well-Being, and Loyalty for the Non-Proﬁt Religious Organization of Volunteer Tourism

: The present research aimed to explore volunteer travelers’ loyalty formation for the non-proﬁt religious organization of volunteer tourism by considering the gender inﬂuence. A quantitative process along with a survey method was utilized to attain the research purpose. Our empirical results showed that awareness of the need, performance of the organization, attitude, and the mental well-being were critical contributors to increasing loyalty. Attitude and mental well-being were vital mediators. The performance of the non-proﬁt religious organization included a comparative importance in building loyalty. In addition, gender moderated the e ﬀ ect of awareness of the need and performance of the organization on the travelers’ attitudes toward it. As very little is known about volunteer tourists’ behaviors, the current study satisfactorily provides an apparent comprehension regarding how their loyalty for the non-proﬁt religious organization is generated and what factors drive this loyalty.


Introduction
Fostering individuals' altruistic travel behaviors is an essential facet of moving toward a responsible tourism future across the world [1][2][3]. Undoubtedly, volunteer tourism activities are altruistic behaviors that are considered as a critical form of this type of responsible tourism [4][5][6]. According to Brown [7], international volunteer tourism can be dated back to around 1915. Although a debate/critique exists, tourism scholars generally agree that the concept of volunteer tourism comprises of the basic meaning of helping communities in certain contexts, which include helping disaster victims or relief, improving the well-being of local communities, protecting the environment, habitat, or endangered species, and distributing necessities and resources [2][3][4]7]. Volunteer tourism is certainly an emerging tourism phenomenon, which is drawing increasing attention from international travelers [5,8].
Concurrently, diverse volunteer tourism organizations nowadays play a key role in this fast-growing tourism sector [1,2]. Particularly, non-profit religious organizations are major players in boosting the growth of volunteer tourism [5]. Nonetheless, due to the abundant number of these types of organizations and the reduced capacity of them in the tourism marketplace, the key issue among non-profit religious volunteer tourism organizations is the long-term survival [1]. Building loyalty that contributes to maintaining the existing volunteers and attracting/recruiting new volunteer travelers is therefore becoming the fundamental requisite of the success of the non-profit religious volunteer tourism organizations. cross-cultural exchange and economic consumption are simultaneously performed while staying in other regions, away from the daily life [18]. There have been many previous studies that proposed a definition and concept of volunteer tourism in various aspects. Wearing [19] defined volunteer tourism as taking vacations to help people with material poverty or to participate in natural environment, cultural heritage maintenance, and restoration work. McGehee and Santos [20] defined paying time and money while traveling outside of one's daily activities to help communities or people in need. Common characteristics can be seen in the definition and concepts of volunteer tourism suggested in aforementioned previous studies. Volunteer tourism originates from altruistic motives of travelers such as environmental conservation and poverty alleviation [18,21]. Such motivation is a combination of unpaid voluntary activities and tourism elements such as vacation, and most of them are served by specialized organizations (including NGO organizations) or groups [22].

Non-Profit Religious Organization
A number of prior studies have explored volunteer tourism performed by non-specified groups [7,[23][24][25][26]. A great deal of previous studies discussed limited aspects such as their profiles, motivation factors, and performed experiences [27,28]. For example, Lo and Lee [27] examined the motivational factors, and identified the five key motives by conducting in-depth interviews with the volunteer tourists: cultural experience with local communities, desire to give away, shared experience with family, religious involvement, and escape from daily hustle. Unsurprisingly, "religious involvement" was one of the motives for volunteer travel, as all participants in the focus group were Christians. They stated that they wanted to help poor communities, and they also preached and hoped that the locals would "accept God's grace" [27]. However, the central motives of volunteer tourists from the previous studies identified include altruism [23,25], egoistic [23,26], and social and psychological demands [25], which are different from motives of members' participating in a religious group. Likewise, the motivation for volunteer tourism can vary depending on who the participants are and who is the host, such as non-governmental organizations, schools and religious groups. Yet, little has been discussed regarding what factors drive religious tourists to engage in and generate loyalty. In that sense, the current study contributes to the body of volunteer tourism literature with substantive findings.

Awareness of the Need for Aid
Schewartz [29] defined awareness of need as any type of actual or potential deficit of required, wanted, or generally owned resources that are desired by an individual, group, or a social class. Steg and De Groot [30] asserted that awareness of need is composed of a similar basis of norm-activation theory that influences human prosocial intention or behavior. For our purposes, we define awareness of need for aid as the extent to which volunteer tourism is believed to have a positive impact on the receiving community.
Campbell [31] cited the growth of various volunteer organizations and programs as strong evidence that aid demand has also increased significantly. Accordingly, for the past few decades, travelers' awareness/concern of the seriousness of social, environmental, economic, and ecological problems of local destination communities has considerably increased [1,9,32,33]. It plays a vital role in travelers' product/service/brand choices in the tourism industry [2,7,34,35] as well as in travelers' altruistic intention [9,13,36]. Furthermore, travelers' awareness level related to the need for help plays as a crucial activator of personal moral obligations in their pro-social decision-making process [5,13]. For instance, Lind et al. [13] showed that high level of awareness of environmental issues leads to sustainable behavior using ecologically friendly travel mode in city. In the volunteer tourism segment, awareness of the need indicates the travelers' conscious level of the local communities' and the local people's need for help [5]. As a cognitive concept, this type of awareness of need is often considered as a critical driver of the travelers' favorable attitude and as a crucial constituent to explain the altruistic decision/loyalty formation [1,32,35]. Hypothesis 1. Awareness of the need contains a positive influence on attitude toward the non-profit religious organization.

Hypothesis 2.
Awareness of the need contains a positive influence on loyalty for the non-profit religious organization.

Performance of the Non-Profit Religious Organization
Performance is regarded as an assessment process of the excellence or mediocrity of a particular corporation/brand and its attributes against other rival corporations/brands [15,37]. The term performance is often alternatively utilized with quality in the consumer behavior literature [14]. In the same manner, performance indicates the volunteers' evaluation process about the quality of the non-profit religious volunteer tourism organization and its program in the present research. The volunteer tourism organization provide travelers experiences of self-fulfillment, changes in values, personal enhancements, and escapism/pleasure [2,7,8]. Accordingly, when volunteers have a positive evaluation of these types of experiences, they perceive a high performance of the organization and its program. The travelers' perceived level of performance of the organization serves a crucial role for the organization to achieve its goals and provide them with satisfactory experiences [14,38].
Recent studies indicated that travelers' perception regarding the performance of the organization considerably affects their decision-making process [37][38][39]. In particular, Kang et al. [39] found that performance and its attributes significantly influence travelers' attitudes and values in the mega-event context. More recently, Al-Ansi and Han [37] demonstrated that excellent destination performance induces Muslim travelers' high value perception, favorable attitude toward the destination, and loyalty for it in the halal tourism sector. Their result was consistent with Song et al.'s [38] earlier research, which demonstrated the significant role of festival performance in engendering travelers' fulfillment, positive attitude, and support intention. In reference to such empirical evidence, we propose that performance of the non-profit religious organization significantly affects attitude toward it and loyalty for the organization among volunteer travelers in the present research.

Hypothesis 3.
Performance of the non-profit religious organization contains a positive influence on attitude toward the non-profit religious organization.

Hypothesis 4.
Performance of the non-profit religious organization contains a positive influence on loyalty for the non-profit religious organization.

Attitude toward the Non-Profit Religious Organization
Individuals' attitude is undoubtedly a core process in eliciting travelers' positive behaviors and loyalty for the organization [10,17]. Attitude is one's general tendency toward a specific entity [40]. The entity can be an organization, a product, a service, a company, or a brand [17]. The term attitude is frequently included in social-psychological theories, since it has a substantial impact on individuals' decision formation for this type of entity [10,41]. The existing empirical studies supported the associations among traveler attitude toward the corporation/brand, mental well-being, and loyalty [41][42][43][44]. Stark et al. [44] examined children's traveler behaviors and demonstrated the associations among mental/psychological well-being, travel-related attitude, and preference. Rodríguez-Arauz et al. [43] investigated food attitudes and well-being and found the important relationship between these two variables. Their finding also revealed that the relationship is under the effect of culture. In the tourism sector, Moon et al. [42] discovered that travelers' favorable attitude toward an airport is formed based on the good quality of the airports physical surroundings, which help them feel relaxed, calm, and pleased. Their empirical outcome also indicated that these positive mental health outcomes result in travelers' fulfilled experiences with the airport use and loyalty for the airport. In accordance with these studies, the subsequent hypotheses were developed.

Hypothesis 5.
Attitude toward the non-profit religious organization contains a positive influence on mental well-being.

Hypothesis 6.
Attitude toward the non-profit religious organization contains a positive influence on loyalty for the non-profit religious organization.

Mental Well-Being
Well-being means travelers' appraisal of the extent that a tourism product attributes to their life quality improvement [45]. Consistently, mental well-being indicates the travelers' evaluation of the extent that a specific product boosts their life quality in a mental aspect, which includes mental/psychological health, during their product consumption. According to Hwang and Hyun [46], travelers can be calm/comfortable, pleased, and refreshed when they experience positive mental well-being. The elevations of mental well-being often enhance the central outcomes of a firm/organization, which include consumer loyalty, retention rate, and the overall image [47,48]. Specifically, in individuals' loyalty generation process or retention process, mental well-being is regarded as the core variable [45,[48][49][50]. In the retail service sector, Troebs et al. [48] found that customer well-being is a significant contributor to elevating loyalty intentions and increasing gratitude and reciprocity. In the business context, Nadinloyi et al. [50] uncovered that employees' mental health is significantly associated with job satisfaction. Their findings also revealed that the unhealthy conditions of employees' mental health, which include feelings of stress, frustration, and burnout, have a negative influence on affective dispositions and on the company itself, which cause turnovers, absenteeism, and complaints. Kim et al. [45] explored the role of travelers' mental well-being and the empirical results showed that mental well-being is a crucial determinant of travelers' positive post-purchase decisions for a corporation. Based on this evidence, volunteer travelers' mental well-being is expected to lead toward loyalty enhancement for an organization.

Hypothesis 7.
Mental well-being contains a positive influence on loyalty for the non-profit religious organization.

Influence of Gender
The effect of gender on most of the studies in social behavior is ground in social role theory and evolutionary psychology. According to social role theory, men and women are socialized in dissimilar ways and perform different roles in society under the assumption that people are passively given their role [51,52]. Similarly, evolutionary psychology explains the sex differences but in terms of biological adaptation. It investigated the differences between men and women by examining the various reproductive problems and linking them with psychological and behavioral characteristics [52]. Evolutionary psychology indicates that gender disparity performs a critical role in sustaining dispositions, characteristics, and patterns of social behavior [51,52].
Despite the importance of gender in social behavior, there are controversial arguments in regard to moderating role of gender. For example, Eagly and Crowley [53] performed a meta-analysis on gender disparity in helping behavior and altruism. Although their meta-analysis is based on social role theory, they concluded that it is not necessary to observe an overall effect size on gender difference in helping behavior. On the other hand, Alexander [54] observed the effect of gender on the influence of a volunteer tourism experience using a quasi-experimental study. She found certain differences in trait scores at the start due to genetic and environmental factors, and it is noteworthy to be aware of a fundamental difference. Likewise, there have been contradicting results among prior studies in moderating role of gender difference in altruistic behavior, and our study tries to fill this void.
In recent decades, scholars in various fields have studied many interesting research topics pertinent to the impact of demographic characteristics on patrons' decision-making and consumption practice [9,[55][56][57]. Specifically, the essential role of gender in tourists' intention is frequently emphasized by the extant studies in tourism industry [16,55,58]. These researchers agree that gender is one of the most fundamental socio-demographic variables affecting tourists' diverse post-purchase decision formation/behavior.
The existing tourism studies indicated that tourists' cognitive, attitudinal, and affective processes associated with their consumption decision are under the influence of gender [16,55,56,58]. For example, Wang et al. [58] identified that the relationships among affective and cognitive images, its antecedents, and its outcome variable are moderated by gender. Hwang and Kim [16] discovered that gender as a socio-demographic factor played an important moderating part in inducing the loyalty generation process for hospitality products. Similarly, Han et al. [55] demonstrated that gender exerted a substantial moderating effect over loyalty formation in the bicycle tourism sector. In addition, Hwang et al. [56] also identified that the cognitive and attitude association and the influence of such a relationship on intention are significantly affected by gender. The aforementioned studies demonstrated the significant moderating characteristics of gender in explicating tourists' behaviors and uncovered the disparity across male and female tourists' behaviors. Gender is irrefutably an essential socio-demographic concept in tourism industry [58]. Hence, comprehending the gender difference on tourists' consumption behavior is regarded as a critical requisite of inventing successful customer retention and loyalty enhancement strategies for every tourism organization or company [9]. Based on this, the following hypotheses are suggested.
Hypothesis 8. (a-g) Gender has a significant moderating influence on the associations among awareness of the need, performance of the non-profit religious organization, attitude, mental well-being, and loyalty intention.

Research Framework
The Figure 1 exhibits our projected model, which contains the five variables that explicate the development of the loyalty for the non-profit religious organization among volunteer travelers. The awareness of the need, the performance of the non-profit religious organization, attitude, and the mental well-being were used as the predictors of loyalty intention. In addition, gender was employed as the moderator.

Measures
We adopted the measurement tools from the extant research for our study [1,15,17,30,33]. Study constructs were utilized by a seven-point Likert scale (1 = "strongly disagree" and 7 = "strongly agree"). Specifically, we employed 4 items to evaluate the awareness of the need, which

Measures
We adopted the measurement tools from the extant research for our study [1,15,17,30,33]. Study constructs were utilized by a seven-point Likert scale (1 = "strongly disagree" and 7 = "strongly agree"). Specifically, we employed 4 items to evaluate the awareness of the need, which included through the volunteer tourism program of the Good News Corps, 'I have become aware that people need help'. To measure the performance of the non-profit religious organization, we used 3 items, which included 'the Good News Corps has fulfilled all its promises'. For the assessment of attitude toward the non-profit religious organization, a total of 4 items were utilized, which included 'my evaluation of the Good News Corps' voluntary activities is positive'. In addition, we used 3 items to measure mental well-being, which included that 'the conditions of my life have become excellent after taking part in the volunteer tourism (VT) program of the Good News Corps'. Lastly, we used 2 items to assess loyalty for the non-profit religious organization, which included 'I am passionate about volunteer activities through the VT program of the Good News Corps'. The measures along with study description were contained in our survey questionnaire. The questionnaire was improved based on graduate students' feedback, who accompanied a pretest. Then it was fixed by a comprehensive review of volunteer tourism experts. A series of measurement items is presented in the Appendix A. All measurement items were evaluated using a seven-point scale ranging from strongly disagree (1) to strongly agree (7).

Data Collection and Samples
Survey data were collected at the volunteer tourism festival held by the Good News Corporations. Travelers who completed a year-long volunteer tourism program with the Good News Corporations along with their families were the attendees of the festival. Religious involvement can be a critical motive for volunteer tourism [27]. The program of the Good News Corporation is known as one of the biggest non-profit global volunteer tourism programs worldwide. The festival held by the corporation offers a good opportunity to interact with international volunteer tourists as the major aim of the festival is celebrating the successful completion of their long-term volunteer services. The questionnaires were distributed to the volunteer travelers in the middle of the festival. The surveyors explained the details about our research and the objectives, and then requested the travelers' participation in the survey. The respondents answered the queries in the survey questionnaire onsite. After ensuring survey completeness, the surveyors provided a little present to the respondents as a show of gratitude. Through this data collection procedure, we gained 320 usable responses, which were utilized for the data analysis.
Of the 320 respondents, 44.1% were male volunteer tourists and 55.9% were female volunteer tourists. The average age of the participants was 23.81 years. The respondents' education position was asked, and about 79.7% of the participants reported they hold a university degree (or while in school), followed by 2-year/some college degree holders (or currently enrolled in a 2-year/some college) (13.4%), high school graduates (3.8%), and master's degree holders (or while in school) (3.1%). Regarding the volunteer tourism frequency, about 82.2% of the respondents reported one time, followed by 2 times (7.8%), 4 times (6.3%), and 3 times (3.8%). In terms of the participants' income, about 30.7% indicated an income between USD 25,000 and USD 39,999, followed by under USD 25,000 (30.4%), between USD 40,000 and USD 54,999 (20.7%), between USD 55,000 and USD 69,999 (8.8%), between USD 70,000 and USD 84,999 (5.0%), between USD 85,000 and USD 99,999 (2.2%), and USD 100,000 or higher (2.2%).

Confirmatory Factor Analysis
In order to validate internal and external consistency of our research construct we conduct a confirmatory factor analysis (CFA) using AMOS 20. The result showed our model included adequate fit indices. The result of the composite reliability (CR) assessment indicated sufficient internal consistency and reliability of constructs, as all factor loadings were close or above the cutoff of 0.700 [59] (see Table 1); awareness of the need = 0.878, performance of the non-profit religious organization = 0.859, attitude toward the non-profit religious organization = 0.937, mental well-being = 0.967, and loyalty for the non-profit religious organizations = 0.693. In addition, the average variance extracted (AVE) exceeded the minimum cut-off of 0.500 [59]; awareness of the need = 0.644, performance of the non-profit religious organization = 0.672, attitude toward the non-profit religious organization = 0.787, mental well-being = 0.527, and loyalty for the non-profit religious organizations = 0.531, indicating the convergent validity. Moreover, all AVEs were greater than the squared correlations between the two constructs, which supports discriminant validity.

Structural Equation Modeling
Structural equation modeling (SEM) was developed to test our hypothesized relationships. The overall fit of the SEM met acceptable levels (χ 2 = 266.752, df = 94, p < 0.001, χ 2 /df = 2.838, RMSEA = 0.076, CFI = 0.951, IFI = 0.952, and TLI = 0.938). We examined the prediction power of the projected conceptual framework. Overall, the hypothesized model had a strong ability to predict loyalty for the non-profit religious organization. Specifically, about 84.1% of the total variance in volunteer travelers' loyalty was accounted for by its antecedents. As shown in Figure 2 and Table 2, the model accounted for about 65.3% of the variance in the mental well-being and about 69.9% of the variance in attitude toward the non-profit religious organization. Structural equation modeling (SEM) was developed to test our hypothesized relationships. The overall fit of the SEM met acceptable levels (χ 2 = 266.752, df = 94, p < 0.001, χ 2 /df = 2.838, RMSEA = 0.076, CFI = 0.951, IFI = 0.952, and TLI = 0.938). We examined the prediction power of the projected conceptual framework. Overall, the hypothesized model had a strong ability to predict loyalty for the non-profit religious organization. Specifically, about 84.1% of the total variance in volunteer travelers' loyalty was accounted for by its antecedents. As shown in Figure 2 and Table 2, the model accounted for about 65.3% of the variance in the mental well-being and about 69.9% of the variance in attitude toward the non-profit religious organization.     The proposed effect of awareness of the need was assessed. As anticipated, awareness of the need exerted an important effect on attitude (β = 0.343, p < 0.01) and loyalty (β = 0.253, p < 0.01). This result supported Hypotheses 1 and 2. The hypothesized effect of performance of the non-profit religious organization was tested. Our finding indicated that performance exerted a significant impact on attitude (β = 0.567, p < 0.01) and loyalty (β = 0.265, p < 0.05), which supports Hypotheses 3 and 4. Next, the influence of attitude toward the non-profit religious organization was evaluated and the outcome demonstrated that attitude exerted a critical impact over mental well-being (β = 0.808, p < 0.01). Hence, Hypothesis 5 was supported. However, the effect of attitude on loyalty was not significant (β = 0.205, p > 0.05). Thus, Hypothesis 6 was not supported. Lastly, our finding demonstrated the significant linkage between mental well-being and loyalty (β = 0.322, p < 0.05), which confirmed support of Hypothesis 7.
Regarding the total effect of the research constructs, which is shown in Table 2, the performance of the non-profit religious organization contained the greatest influence on loyalty (β = 0.529, p < 0.01), followed by attitude (β = 0.465, p < 0.01), awareness of the need (β = 0.413, p < 0.01), and mental well-being (β = 0.322, p < 0.05). In regards to the mediating effect of the study variables, the performance of the non-profit religious organization (β = 0.264, p < 0.01) and awareness of the need (β = 0.160, p < 0.01) significantly affected loyalty indirectly through attitude and mental well-being. In addition, attitude included a significant indirect influence on loyalty (β = 0.260, p < 0.05). This outcome suggested attitude and mental well-being played significant mediating roles within our hypothesized model.

Baseline Model and Metric Invariance
The hypothesized influence of gender was assessed. The respondents were split into two groups; men and women. The men's group contained 141 participants, and the women's group included 179 participants. We generated a baseline model comprised of these two gender groups. All factor loads within the baseline model were set to be identical in both groups. The results revealed that the baseline model had a satisfactory adherence to the data. Then, the model was sequentially compared with a chain of nested models by using a chi-square test.

Discussion and Implications
This research aimed to investigate the volunteers' loyalty generation process for non-profit religious volunteer tourism organizations. The proposed theoretical framework involved the intricate associations among the awareness of the need, the performance of the organization, attitude, and the mental well-being. It comprised its influence on loyalty by considering the gender effect. The data collected through the survey methodology was utilized to assess the suggested theoretical model. Our quantitative analysis demonstrated the satisfactory power of the model for predicting volunteer travelers' loyalty. The hypothesized associations linking awareness, performance, attitude, and mental well-being were all generally supported. The moderating influence of gender in generating a positive attitude toward the volunteer tourism organization was uncovered. Overall, the purpose of the study was entirely accomplished.
The individuals' awareness of the need was an essential variable contributing to the increase of the prediction ability of the hypothesized framework. This result implies that enhancing volunteer travelers' concern for local communities' need for help is critical to induce their positive attitude and loyalty for the non-profit religious volunteer tourism organization. From the practical aspect, it is therefore fundamental to encourage volunteers to have high awareness/concern about various problems that the volunteer tourism destinations have, which include environmental pollution, poverty, ecological deteriorations, natural disasters, poor child education, and water shortage, through a variety of advertising campaigns for loyalty building. From the theoretical aspect, our findings generated the notion that when individuals have a strong awareness related to the problematic issues of a volunteer tourism destination, they are likely to have a better attitude toward the volunteer tourism organization and be loyal to it and its program.
Performance of the volunteer tourism organization was found to be the strongest factor among the study variables within the proposed conceptual framework. This finding implies that the performance of the organization is the main aspect of the loyalty generation process for the non-profit religious organization among the volunteer tourists. This result was coherent with the previous studies of tourism/consumer behavior, which emphasized the key role of performance in increasing the predictive ability of a theoretical model for the patrons' loyalty/purchase behavior [7,14,15,23]. Practically, our results highlight that for the effective elicitation of the volunteers' loyalty for the non-profit religious volunteer tourism organization, maximizing the performance of the organization and its program is fundamental. Practitioners of the organization need to make various efforts for boosting such a performance. Theoretically, our finding gives the essential information that is required to better explicate the volunteer travelers' decision/behavior, which necessarily involves the concept of performance into the framework for such a decision/behavior.
The gender moderating effect on the suggested conceptual model was empirically identified. In particular, gender exercised big influence on the magnitude of the association among the awareness of the need, the performance of the organization, and the attitude toward the organization. The relationship between the awareness of the need and the attitude was significantly stronger for men's group (β = 0.527, p < 0.01) than that of women's (β = 0.233, p < 0.01), and the relationship between performance and attitude was significantly stronger for women's group (β = 0.698, p < 0.01) than that of men's (β = 0.367, p < 0.01). This finding provided critical information, because at a similar level of the awareness of the need, male volunteer travelers showed an increase with a more positive attitude toward the volunteer tourism organization than the female travelers, and female travelers showed an increase with a more favorable attitude toward the volunteer tourism organization than male travelers at the similar level of performance perception.
The result of gender moderating effect can be explained by heroism and chivalry, which are intrinsically attributed to males [53,60]. Males take action when help is needed, and this action tends to enhance their self-esteem [53,61]. Therefore, males tend to have a stronger attitude, which is triggered by their intrinsic heroism and chivalry. Similarly, the finding that the relationship between organizational performance and attitude was significantly stronger in the women's group than the men's group, can be accounted for by female social reinforcement and affection towards their close friends [61][62][63]. According to Piliavin, Rodin, and Piliavin [64], females stereotypically attribute more value to the belongingness of social status. Hence, females would care more about their organizational performance than males.
Despite its importance, research on the effect of gender on the volunteer travelers' loyalty formation for the volunteer tourism organization is scant. The present research contained a theoretical value, and this study satisfactorily filled this gap. The evidence of the gender difference demonstrated in the present research provided the essential information that using gender is crucial to clearly know the volunteer travelers' attitude generation process towards non-profit religious organizations. The extant theoretical frameworks in the previous studies pertinent to volunteer travelers behaviors therefore need to be deepened with the integration of the gender effect. Our results also offered practically important information, because for the efficient enhancement of the male travelers' positive attitude toward the volunteer tourism organization, increasing their awareness of the need is important. Meanwhile, for the rapid increase of the female travelers' attitude, improving their perception regarding the performance of the organization is fundamental. The practitioners of the non-profit religious organization should be aware of this gender difference and its criticality when inducing volunteers' favorable attitude.
Very little was known regarding the intricate mechanisms underlying the association among awareness of the need, the performance of the non-profit religious organization, and the loyalty intention in field of volunteer tourism. In this research, we satisfactorily uncovered the mediation mechanism that comprised of attitude and mental well-being, which broadens our comprehension of the processes generating volunteer travelers' loyalty intention. The convoluted mediation mechanism offered the important theoretical information that the effect of awareness of the need and performance of the non-profit religious organization on loyalty intention can be maximized by the dynamic role of attitude toward the non-profit religious organization and mental well-being. Practically, dealing with these mediators is also significant for the efficient elicitation of volunteer travelers' loyalty intention for the non-profit religious organization.
There are few limitations, which offer future research opportunities. First, we develop this study to be adequate in volunteer tourism area, and the interpretation of our results is the most operative in the same circumstance. Hence, we recommend some cautions when applying our outcomes to different types of tourism or other consumer behavior sectors. For example, a replication of the research is needed for future research if one wishes to examine the effectiveness of our proposed conceptual model. Second, the correlation between performance and attitude is about 0.709, which is somewhat high. In order to fully avoid the issue of multi-collinearity, the measurement design should be more carefully conducted in the future research.

Conclusions
Undoubtedly, volunteer travelers' decisions and behaviors pertinent to the volunteer tourism program/organization is one of the crucial issues in the entire tourism industry. However, the volunteer travelers' loyalty generation process especially for the non-profit religious organization and the triggers of such processes have not been fully explored. This research filled this gap. The role of the awareness of the need, the performance of the organization, the attitude toward the organization, and the mental well-being was unearthed in a clear manner and our proposed conceptual model satisfactorily provided relevant evidence. In addition, we clearly explored the gender moderating role. The results of our research can help volunteer tourism practitioners from non-profit religious organizations invent useful tactics to retain existing volunteers and to improve their loyalty by using the variables of this study as tools. The theoretical base related to individuals' decision formation and loyalty in religious volunteer tourism is still in its infancy. Hence, our study contains highly valuable material and originality. The present research could assist subsequent studies about volunteer tourism through non-profit religious organizations.

Conflicts of Interest:
The authors declare no conflict of interest.