The conviction that there is no God is irrational because one cannot prove a negative. (How do you prove that something does not exist?) However, it is entirely rational to not believe in something whose existence has not been demonstrated. I don’t believe in dragons or fairies because no one has yet proved to me that they exist. Ditto God. I am not asserting that God does not exist, but simply saying that I don’t believe in the existence of God because I see no evidence of Him (or Her, or It). This is not a dogmatic position: if you can prove to me tomorrow that God or dragons exist, I will start to believe in them. Until then, I remain in disbelief.
Do read the whole thing.