My elegant suggestion is that, since one series started airing after the other closed shop, and both were on the same network, “God” from “God Friended Me” was the computer program “Friend” from “Person Of Interest” looking for a more peaceful means towards the same goal.
I had to unfriend God. He kept telling me to do crazy stuff like kill my son; then he gave me a plague of boils for no reason and took away all my oxen. With friends like those…