In your opinion what causes christians to believe in Jesus

[Sheldon]

I can conceive of a fully functional elephant with a beachball for a head. I can accept that such a thing is not possible.

This isn't difficult.

Boru

Usage varies.  According to a common usage, to say that you can conceive of something is to imply that it is possible.  So it depends upon what the person means.

Exactly what occurred to me, and had John been a little less mendacious, I'd have prompted him to clarify, but felt no such urge. In discourse and debate, it is entirely incumbent on the person making the primary or larger claim, to ensure clarity in their claims. 

He also immediately went from conceive of, to conceive is possible, without any preamble, and turned the claim I made to not believe something is possible, into a claim it is impossible, despite me making no such claim. I am not about to indulge that sort of sophistry, but nor am I about to explain fully every error in reasoning he makes / is making. Especially as he has shamelessly ignored every question put to him, while stridently demanding I answer questions repeatedly, when he doesn't get the answer he wants.