And how would you verify that the address the NFT is sign with belongs to god?

I would presume God would find a way to make his intentions clear, maybe through his earthly agents in his church.

If you are concerned that this would need to happen off-chain, and I would need to trust my channel to God NFT launch announcement, then you are of course correct, but note that is is not a slight on NFTs.

NFTs are conceptually no different than the "Google Digital Art Marketplace", except people are less concerned it will be shutdown in two years.