Maybe taking a look into eastern asian cultures would be close enough? A good portion of their mythos treat gods as powerful beings that can fall from grace and be defeated. Also, in Chinese Taoism, humans responsible for great deeds can ascend into godhood

Most of India might also provide a very good look into how people who grew into a polytheistic society act and think about their own spirituality. Japanese Shintoism might be the closest look into an “easily accessible” animist look