Although previous research projects have highlighted the pro-environment and pro-sustainability attitudes of traditional spirituality and religions, there is a lack of studies that explore the way in which expressions of different types of religion and spirituality, as well as measures of belief and non-belief, are related to the evocation of sustainable behaviors. This study, conducted with emerging adults, analysed the relationships between measures of the image of God, religious orientation, the importance of religion and spirituality, religious/spiritual experience, paranormal beliefs and non-belief (religious, spiritual and atheism), as well as altruistic, frugal, environmentally-friendly and equitable behaviors. The results were found to be consistent with the pro-environment character attributed to religion, as well as non-traditional forms of spirituality, indicating their link with sustainable behavior, particularly the measures focusing on belief/non-belief. They also highlighted an effect of the measures of religion/spirituality, indicating the benefit of using multivariate approaches of a qualitative and quantitative nature.