"in the absence of evidence for the existence of a god the correct position is atheism."

True enough as a statement, but that's as far as it goes. Atheism, by choice, refuses to acknowledge that evidence for God does exist, and in doing so, cannot reach any other conclusion.

The poster opened with the statement "If God himself came down," which is exactly what happened in the person of Jesus Christ. Refusing to acknowledge this does not make it any less true, it simply puts them in a sad and precarious position.