Cogito, ergo deus non est. (I think, therefor there is no god).
It was a wonderful day indeed when I realized for the first time that religion was a pile of fantastical nonsense. To be free of the oppressive chains of religion and the almighty deity was an amazing insight that made me happier than I'd been in a long time. Yes, it is wisdom and it comes with rational thought.
Knowning "God "does not exist, is wisdom, if you have arrived at that conclusion through a careful and reasoned consideration of the evidence and arguments for and against. Flippancy about the matter is no better than proud belief in commonly held ideas about fantasy figures who supposedly do magical things, like "God" and "Jesus".
I have a quiet pride in being an atheist, because I know I have been through those aforementioned steps, and because I have not been persuaded by the theistic view, even if it is probably the most prevalent one. I have a working brain, and I've used it in this matter.