Take ancient societies. I mean, stuff like Ancient Egypt, Greece, in fact, even during Christian times, you know that a Christian guy came up with the Big Bang. I'm not Christian, however I do think not accepting science and homosexuality is a modern thing for people that want to, well I don't know what they want with that. Religion means, I believe in, let's say Zeus. If I believe in Zeus, do I neglect the way in which lighting happens? No, I just think that Zeus causes the start of the process. The example was vague, but you get what I mean.
Reason and religion can certainly coexist. Many facets of modern religion can be traced back and reason can be found within them. You can trace events that were written about in the Bible to actual events that happened in history, and you can analyze the reasons behind them, because they actually happened.
Reason and religion cannot coexist for the simple and straight reason that religion requires a belief in deities. However, the belief in deities itself is irrational. If we evaluate the belief in deities with perfect reasoning, we realize that it is impossible to believe in gods and still be reasonable. I'm not saying theists are completely irrational, but the belief is. Why? Because the existence of gods cannot be proven. Gods exists in our minds, yes, anything can live within our minds and it's fine, but not in reality.