Good reasons for that - say, for example, there is a volcanic eruption. We can see what evidence is produced by this volcanic eruption - lava flows that solidify into rock, layers of ash, etc.
Then we come across layers of rock that look just like the lava flows of the observed volcanic eruption. We find layers of lithified ask, with characteristics just like the ash layers we saw forming during the eruption.
You will have us shrug our shoulders and draw no conclusions because these geological features could have been created by jesus 300 years ago or whatever nonsense you propose.
Sane, sensible, educated people will draw logical conclusions. Religious kooks will dismiss for no good reason.
From the fellow that thinks stories from the ancient middle east carry more weight than actual observation...