Generally speaking, SCPs based on Abrahamic religions don't go over well. I think that's for basically two reasons: (A) because you can't assert the existence of the divine with sufficient rigor, and (B) because Abrahamic religions have been done to death. So I'm trying to do something different.
This SCP is the Holy of Holies of a lost Abrahamic religion, which is conceptually something like promethean Judaism or inverted Gnosticism. This deity did something horrifying in prehistory, without which mankind would never have existed. The veil surrounding the innermost sanctum of his temple doesn't exist to protect mankind from the glory of God. It exists to hide God from the consequences.
In any case, I am operating with a very small margin of error, if what I am attempting is possible at all. Here's a link to my sandbox: