In your opinion what causes christians to believe in Jesus

[Sheldon]

That’s not really how it works. You observe it raining, and then gather evidence by looking at the grass. If you haven’t observed the rain (or gotten EVIDENCE of a recent rainfall), you can reasonably conclude that something other than rain made the grass wet. What your scenario does is test the hypothesis that rain is the only thing that makes grass wet.

You're very close. Obviously, if you observed the rain itself it's pointless to look for evidence. The question is, if you didn't see the rain, would the wet grass be evidence for it? You're right that the answer is no, and you're right that it's because rain isn't the only thing that predicts wet grass.

But the broader conclusion I want you to draw, is that nothing you replace "wet grass" with can confirm that it rained. And anything you attempt to use as evidence, no matter how reasonable it might seem, will always be a logical fallacy.

That's why science doesn't confirm, doesn't evidence, doesn't prove or affirm anything. It does only one thing: falsify.

Falsifying anything in science requires evidence, you are comically wrong here.