There are two men. One is a theist and the other an atheist. Each lives out his life according to his creed, and in the end both men have to die. Let us say for the sake of argument that when the theist dies there is no God. He believed in God, but in the end there was no God.
Death comes and life is over, finished, the end.
No loss, no gain, it's simply over. On the other hand the atheist dies and he was wrong. It's too late. He again takes birth in the material world and suffers and enjoys according to the deeds of his past life. So to be an atheist, one has to admit, is quite a risky proposition.