I don't consider theism to be different in any important way from atheism. The distinction is about whether or not we believe in the existence of something for which there is no proof. I don't, on the basis of that, but I also understand that as far as we come on the "how", we may never come so far on the "why", and there is a basic yearning in all of us to assign meaning to existence, and to (try to) understand our own consciousness.
Religion is...interesting. Religions often seem to result in folks making specific claims about the earthly lives which we all share -- whether it's human ethics or the physical nature of the world -- and submitting that these are divine truths and not merely one among many of the different, fluid human schools of thought. This doesn't apply to all religious people or maybe even most. Certainly not to the well-spoken folks of this forum, who articulate their points very well.
Among these are for example, views traditionally passed down about nonbelievers. Or nowadays, vies on homosexuality, which vary from church to church even within a religion.
I think there are good reasons for religion and good positive effects that come out of it. Religions are a strong way of maintaining cohesion, unity, and values among a widespread group of people over time. By having these debates internally, updated values spread slowly, but safely (akin to the U.S. model for laws? Adopt later than earlier and avoid caprice). I mean, that is generally how things work and for any organization it's sensible to have a high bar for change. The downside is that it results in people sometimes being severely locked into being behind the curve, because to change a view, they would have to reinterpret their holy book. In the meantime, they often take those who have adopted the change as partakers in an ideological assault on their own divine institution.
I don't think this is the only way to go, for us humans. I think the modern world is connected enough to start tearing down these barriers and perhaps
building new ways forward? Humans are very good at developing and updating our social institutions. We made religion, the greatest instrument in our written history to date, and we can surely update and transform it for future ages. Along the way, we'll never really lose the best teachings and traditions developed in our past, and we'll never stop grappling with the curious questions of meaning and theism -- though hopefully, we'll no longer have need one day for these lines in the sand.