An old book but seems interesting and explains the biological functions of religions well, so I recommend it here.
Religion is Not about God: How Spiritual Traditions Nurture our Biological Nature and What to Expect When They FailLoyal Rue
2004
Thousands of religious traditions have appeared over the course of human history but only a relative few have survived. Some speak of a myriad of gods, others of only one, and some recognize no gods at all. Volumes have been written attempting to prove the existence or nonexistence of supernatural being(s). So, if religion is not about God , then what is it about? In this provocative book, Loyal Rue contends that religion, very basically, is about us . Successful religions are narrative (myth) traditions that influence human nature so that we might think, feel, and act in ways that are good for us, both individually and collectively. Through the use of images, symbols, and rituals, religion promotes reproductive fitness and survival through the facilitation of harmonious social relations. Drawing on examples from the major traditions—Judaism, Christianity, Islam, Hinduism, and Buddhism—Rue shows how each religion, in its own way, has guided human behavior to advance the twin goals of personal fulfillment and social coherence. As all faiths are increasingly faced with a crisis of intellectual plausibility and moral relevance, this book presents a compelling and positive view of the centrality and meaning of religion.
YouTube:
Loyal Rue: Religion Is Not About God
2006
https://youtu.be/JH493NsM31YLoyal Rue presenting the central concept of his 2006 book,
Religion Is Not About God, at the Beyond Belief Conference held in California in 2006. Rue is a philosopher and natural historian of cultures, and he is one of the leaders of both the scholarly endeavor to understand the evolutionary roots and functions of religion and the cultural movement to bring a mainstream understanding of "big history" (aka, the "epic of evolution") into prominence as a secular, religious, and moral resource.