Tsipras will sooner of later see the light and accept the inevitable. A grexit would kill his country's economy and he knows it. I think he hopes that the EU is sufficiently afraid of a break up of the Euro to blink firms but Angela has made it clear that a grexit would be a lesser evil.
Oh, and there really nothing like an atheist. Every person alive worships something. Some worship themselves, others worship money, wealth or power, some worship other people while others worship the living God Etc.
Great men are not always wise, neither do the aged understand judgement...