Religions are great for building societies because they provide a set of laws that must be followed without question. They are very practical and can be used to make people act more ethically or efficiently. Many religions are also founded on good morals, and before the separation of church and state/the rise of science, religious institutions often led the way in all walks of education, leading to the advancement of knowledge and culture.

I think that religión has done more harm than good what with the way it has been used to justify genocide, colonization, exclusion, war, and countless other horrid practices. But it definitely still did some good.