Wrong to not believe in God or a deity? No. Wrong to not believe in something? Yes.
A person has to have their own beliefs regardless of whether or not they are mythological or supernatural. It's almost painful to see so many Atheists who claim to believe in nothing. Atheism is and never was the belief in nothing. Atheism, in the broadest definition, is the rejection of believe
in the existence of deities. I don't believe in God, I don't believe in any other gods, I don't believe in destiny, I don't believe in karma, and I don't believe in fate. What I do believe is my complete control over my own life.
Truly I've grown out of trying to bastardize religion. I'm even okay with the concept. What I'm not okay with is organized religion as a whole. I can't say what it does for individuals, but as a whole, I see it doing nothing but ruling over the lives of its believers. I think the quote from Dogma sets it up the best:
"No, "Through the Looking Glass". That poem, "The Walrus and the Carpenter," that's an indictment of organized religion. The walrus, with his girth and his good nature, he obviously represents either Buddha, or, or with his tusks, the Hindu elephant god, Lord Ganesha. That takes care of your Eastern religions. Now the carpenter, which is an obvious reference to Jesus Christ, who was raised a carpenter's son, he represents the Western religions. Now in the poem, what do they do? What do they do? They, they dupe all these oysters into following them and then proceed to shuck and devour the helpless creatures en masse. I don't know what that says to you, but to me it says that following these faiths based on mythological figures ensures the destruction of one's inner being. Organized religion destroys who we are by inhibiting our actions, by inhibiting our decisions out of, out of fear of some, some intangible parent figure who, who shakes a finger at us from thousands of years ago and says, and says, "Do it... do it and I'll fuckin' spank you."