In your opinion what causes christians to believe in Jesus

[Belacqua]

That it's disconfirmed.

Wrong. It may be that after the rain the sun came out again and dried it up (I live in Texas, sunshowers are a regular event), or it may mean that you saw rain falling but that the Earth's radiant heat evaporated the water quickly.

So what appears to be straightforward objective evidence (dry grass = no rain) in fact depends on a great deal of prior knowledge if we are to interpret it correctly.