If aliens don't exist, the universe is sure a waste of space. :D
Actually, there is another definition for anti-theist, someone who believes there is a God but is opposed to God. I kinda like that one, if God did ask Abraham to sacrifice his son, then that is a God I would be opposed to. Fortunately for me, I don't believe that God exists.
I used to be an atheist, but since I have changed my mind. This is the reason why. I accept the science as we currently know it about the Big Bang to the present, it makes a good deal of logical sense. However, the beginning of our universe seems to need a cause, something springing out of nothing doesn't seem logical. This can be answered by making our universe just one in a repeating chain of universes, there is no beginning, there is no end. So how does God figure into that? It seems logical that at some point along this chain of universes that something would evolve to such a state of intelligence that it could figure out how to survive into the next universe and continue on, perhaps even shaping the next universe to what it wanted. That sounds godlike to me. The other is the universe as God, both the creator and the creation, endlessly changing. That sounds Godlike.