“...nearly two thousand years after one man had been nailed to a tree for saying how great it would be to be nice to people for a change..."
― Douglas Adams, The Hitchhiker’s Guide to the Galaxy

Crowley: What was it he said that got everyone so upset?

Aziraphale: “Be kind to each other.”

Crowley: Oh yeah, that’ll do it.

(From Good Omens. I swear this scene was in the book as well but I can’t find the passage.)