Better believe in the jealous God. If you are right, he won’t punish you and might even grant you some favours. If you are wrong and it turns out that there is no God, well, you won’t lose anything
Pascal’s wager
This is the Pascal’s wager, the argument given by French mathematician in Pensees (Thoughts) in favour of belief in God.
There are flaws, but we can still see in it the confluence of important strands of thought: Decision theory (used for the first time in history), pragmatism and voluntarism (the thesis that belief is a matter of the will), according to the Stanford Encyclopedia of Philosophy
Not enough evidence, God!
You feign belief to please God. But what if he is omniscient? Asked what he’d say if God appeared and asked why he failed to believe, Bertrand Russell said he would tell the almighty, “Not enough evidence, God! Not enough evidence.”
Choosing the wrong God
And what if you bet on the wrong God? “Suppose the God who confronts you when you die turns out to be Baal, and Baal is just as jealous as his old rival Yahweh was said to be, mightn’t Pascal have been better off wagering on no God rather than on the wrong God?” quips evolutionary biologist Richard Dawkins
The ludicrous idea that believing is something you can decide to do is deliciously mocked by Douglas Adams in Dirk Gently’s Holistic Detective Agency, where we meet the robotic Electric Monk, a labour-saving device that you buy ‘to do your believing for you’. The deluxe model is advertised as ‘Capable of believing things they wouldn’t believe in Salt Lake City’.