I didn't say we were waiting for him to BE a Christian, I said we were waiting for him to SHOW it. The meme says nothing about whether he is one; it says there's no proverbial fruit. And if there's one basic way to show it, it's to just say, specifically, what you believe.
There's a lot of other stuff on the list of "things Trump says/does that aren't consistent with the Christian faith", but I only have so much space in a meme.