The present study aimed to evaluate the soldiers' PWB and SWB, as well as the relationship between these two concepts. Our results demonstrated that soldiers' PWB was at a high level. These findings, which are consistent with the results of studies by Lan et al. (
26) and Mirandola et al. (
27), can be justified by the fact that numerous individual and group responsibilities are assigned to soldiers during their military service. In other words, high self-efficacy in doing tasks helps soldiers to face the problems appropriately and experience a higher level of PWB. Furthermore, soldiers are the human capital for future social activities; so, they receive higher social support, which improves their satisfaction, life expectancy, self-esteem, stability of mood, personal health, and satisfaction. Ultimately, these factors increase PWB in soldiers. In this regard, Sharma and Nagle believe that individuals with high PWB can resist social pressures to think and act in certain ways; they Have self-regulatory behavior and evaluate themselves by personal standards (
28). On the contrary, He et al. (2018) carried out a study in Australia and showed that PWB was low in postgraduate nursing students (
29). This finding can be justified by taking into account that the study population and environmental mastery were different between the mentioned study and our research. In Iran, Seyedi et al. (2016) stated that the inability to have individual planning due to the closed atmosphere of military barracks, lack of attention to soldiers' specialized capacities, social problems such as being away from the family, and economic problems can pose a serious threat to soldiers' PWB (
30). Moreover, the results of the present study demonstrated that the lowest PWB mean score was related to the “Purpose in life” subscale, while the highest score was associated with the “Environmental mastery” subscale. This result is in agreement with studies by Sagone et al. (
31) and Pasandideh et al. (
32). In explaining the soldiers' low scores in "Purpose in life", soldiers believed that the military service was very long and wasted their time. They reported the loss of employment and academic/social opportunities, economic problems, and delay in marriage as the disadvantages of going to the military service. Participants' high scores in "Environmental mastery" can be explained by the fact that the military service improves the soldiers' skills in social relationships, interpersonal and group communication, responsibility fulfillment, and independence maintenance, which can consequently affect their live performance.
The results of the present study showed that soldiers had high SWB. Other studies in Iran (
33-
35) and the USA (
36) are in line with the present study. Perhaps, one reason for the high SWB score in soldiers is the cultural and social characteristics that dominate the Iranian society. In Iranian culture, spirituality is intertwined with religion so that the senior military leaders consider holding religious ceremonies in military barracks.
The results also showed a significant positive correlation between SWB and PWB, which is consistent with other studies (
37-
40). Unterrainer et al. (2014), in a review study, reported that spirituality was associated with the promotion of psychological and personality components (
40). Holland et al. (2016) investigated young couples and showed that SWB had a direct and strong relationship with PWB and increased the couples' intimacy (
41). Aflakseir (2012) found that PWB had a significant relationship with SWB among British Muslim students (
42). O’Connor studied people living with leukemia and indicated that spiritual health was significantly associated with PWB; an increase in spiritual health decreased hopelessness, inadequacy, frustration, and anxiety problems (
43). On the contrary, Meanly et al. (2016) showed that spiritual health was inversely related to PWB in young gay and bisexual men so that PWB decreased with increased spirituality (
44). Perhaps, one reason for this discrepancy in the results can be the difference in research communities and cultural characteristics of the two countries under study.
Although our results showed that SWB was not significantly correlated with the dimensions of Autonomy and Purpose in life, Jafari et al. mentioned that People who have higher spiritual health, are more satisfied in life and act more purposefully (
45). The discrepancy in the results of the present study can be due to the presence of soldiers in a closed military atmosphere, inappropriate behaviors of the military personnel, and lack of considering the soldiers' expertise. Another justification can be the fact that soldiers believed that military service was a hindrance to the immediate accomplishment of their life goals (
30).
This study had three limitations. First, the application of self-report questionnaires could cause bias in the results. The second limitation was the lack of permission to research various military barracks. The third limitation was attributed to the application of a convenience sampling method; the random sampling method was not possible because the researchers were not provided with the soldiers' names considering the military officers' discretion. As a result, future researchers are proposed to conduct studies with larger sample sizes using random sampling methods and comparative designs among several military barracks. Moreover, more interventional and combination studies are recommended in the field of PWB, such as resiliency and social support, to enhance soldiers’ autonomy and purpose in life.
The results showed that PWB and SWB were at a high level among the soldiers. Furthermore, the findings confirmed the positive and significant role of SWB in soldiers' PWB. Therefore, it can be concluded that having a satisfying relationship with God helps soldiers to endure many negative events and stressful conditions in the military barracks' environment. In general, spiritual health is associated with the promotion of environmental mastery, positive relationships, and self-acceptance, which can play a vital role in enhancing soldiers' mental health and thereby improving their PWB.