Atheists, tell me, a Roman Catholic: why should I become an atheist?

[Tonus]

Atheists, why do you reject the idea of God, and why should I? I know that your answers will include "there's no evidence" and all that, but please try to explain.

I am not sure what you mean by "reject the idea of God." I am not convinced that God exists because aside from the lack of evidence is the lack of an actual God showing up and the lack of consensus among the billions of people who claim with certainty that one (or more) exists. I don't think that there has been a religion yet founded that made sense once you got past the surface glitter.

However, I cannot answer the question of why you should reject the idea of God. If you find that your faith is faltering, investigate that. Why does your faith seem to be weaker? What do you think would make it stronger? Weaker? What do your fellow believers think the problem might be, and does their reasoning make sense? Or does it just make the issue more confusing?

Don't just ask the atheists here why you should become one. Ask the theists why you shouldn't. See if their explanations help you find whatever it is you're looking for.