John Kelly says he's being punished by God ... and that's why he's working as Donald Trump's Chief of Staff.
Gen. Kelly made the joke Thursday at a Homeland Security event, where he was addressing his former colleagues at the department -- which he used to run. He says he must've done something wrong ... and the man upstairs took notice.
He also told his old crew he missed them ... the implication ... working for 45 ain't no walk in the park.
Ya gotta wonder if DT's gonna be pissed over this -- even if Kelly was clearly saying it in jest. Probably ... most definitely.