Why shouldn't there be a god/ celestial entity?

What is the point in not beliving in some sort of god? I mean if there is a god and you're a religious person and a good person, then you're set when you die. But if there is no god and you're a religious person and a good person and there is no god, then at least you're remembered as a good person.

On the opposite side of the spectrum, if you do not belive in any sort of god, and there is, you might very well be in trouble when you die.

So is not having a religion worth it.