Atheism is a belief by the atheist that there is no credible, verifiable evidence that satisfies the atheist that there is a God. The "mathematician's" opinions about his particular version of God are just that - opinions - and not verifiable evidence. His belief in his particular version of God is based on faith and not on evidence. If he and his followers get comfort from that, that is great. Please don't attempt to make others feel guilty or afraid for not agreeing with the faith-based beliefs in his particular God.
