Presupposes two things -
1. The belief of an atheist definately translates to an actual reality.
2. God actually cares whether or not you believe in him rather than how you act.
I think both are, at the very least, baseless. The stance of the atheist representative of the scientific/intellectual kind is one of a probabilistic rejection of all known current models of God, not a belief concieved as actual facts regarding any or all possible Gods. At least IMO, that is how it should be, since to go any further right now would be to indulge the same irrationality we criticise the theists for having.