Amid intensifying global environmental crises, growing scholarly attention has turned to the role of religion in shaping pro-environmental behavior. This study compares the influence of Islamic and Christian teachings on environmental behavior among Muslims in Iran (N = 442) and Christians in Germany (N = 58), using a researcher-designed questionnaire and nonparametric statistical methods, including direct cross-national comparison of key associations. Among Iranian Muslims, religiosity and religious socialization were positively associated with pro-environmental behavior and a sense of environmental responsibility, underscoring the ethical potential of Islamic concepts such as khilafah (stewardship), the sacredness of creation, and moral responsibility toward nature. However, religiosity was negatively related to general environmental awareness and showed no significant association with low-consumption practices or beliefs about the harms of consumerism. Moreover, religious institutions and leaders in Iran were perceived as playing a limited role in environmental engagement. Among Christians in Germany, institutional religiosity showed no significant relationship with environmental behavior, awareness, or responsibility, while pro-environmental behavior was shaped primarily by secular norms, environmental education, and civic culture. Direct cross-national comparisons confirmed that the association between religiosity and both environmental behavior and religious awareness was significantly stronger in Iran than in Germany, whereas the relationship between environmental behavior and religious socialization was comparably strong in both countries.



The findings demonstrate that religion’s influence on environmental behavior is context-dependent and mediated by cultural, institutional, and social conditions. In Iran, religion remains closely connected to collective identity and moral socialization, while in Germany environmental values are largely embedded in secular institutions and civic culture. The study concludes that religious traditions can contribute to sustainability when their ethical resources are effectively connected with contemporary ecological knowledge and social practices.