Iconostasis, edit 2: Caleb, Mark, Joseph, Matt, Achebe

[Achebe]

So the meaning is something on the lines of - once piety has turned you away from feeling humanly emotions, it's best to cover up that cold, hard inside with gaudy, warm colours, a neat distraction from reality. Both for the onlooker and perhaps the icon himself. Without that distraction, and faced with reality, one's messy humanity will catch up again.
Interesting. Quite smart, actually.
I like it a a lot.

Would it read better in the third person?

Piety turns
the heart to stone.

Now cover this rock
in gold leaf, the delicate
browns of flesh, in flashes
of red and rich azure;
let it not remain gray,
empty, almost modern,

ultimately the kinder home to moss
which knows only compromise.