In your opinion what causes christians to believe in Jesus

[The Architect Of Fate]

And where does "selection pressures" come from? The environment.

Among other things 

Okay, then let's run the thought experiment: We see species that look like rocks in environments full of rocks, and species that look like leaves in environments full of leaves. If we build a room full of beachballs and drop a simple organism in there, is it not possible that they begin to display beachball-like traits over the span of millennia?

Also yes the creature will adopt pattern etc that resemble it's environment over time even artificial environments  not sure why you think that's an issue 

To me, it's intellectually lazy not to be able to even contemplate the possibility of things. (And unhealthy as well, since finding possibility is a key antidote to depression.)

Considering you use possibility as an escape hatch to believe in silly things without a lick of evidence is both unhealthy and lazy