This is complicated in the case of religious beliefs where the deity will judge you by your beliefs and not just your actions.
It is also complicated in the case of religious beliefs where other human beings will judge you by your beliefs, which is one reason why abandoning religions is so hard. But that is off-topic, particularly as you can just lie.
It has been claimed on this site that the fundamental question of rationality is "What do you believe, and why do you believe it?".
A good question it is, but I claim there is another of equal importance. I ask you, Less Wrong...
What are you doing?
And why are you doing it?