Well, let me qualify, rational atheists do not exist, and I can prove it! First let us define the terms. By rational I mean able to reason. By atheist I mean one who denies the existence of God. By God lets just say a supreme being, for God is nearly as impossible to define in a single sentence as God is to prove (which can not be done.)
Now to get to it and it's simple really. How can any reasonable person expect to argue the none existence of something that can't even be defined. If you say that I am jumping the gun on God not being able to be defined than I say, define God and then say that that God does not exist. Fine, I will concede that the God of your limited definition may not exist assuming you have some proof, however, what of God of other's definitions. You can not possibly even know all possible definitions of God therefore could not even argue the non existence of all things you don't know about.
Therefore the statement of atheists that God does not exist is a statement of faith not a statement of what is reasoned. You may say as is any faith but what is more reasonable to have faith in something you can not prove or to have faith in the absence of something you can neither prove nor disprove.
So in conclusion if by my ramblings we have not made any more Christians, at least we now know atheists do not exist.