Nick Cannon -- I Finally Got Mariah Carey Off My Back!

Nick Cannon will be divorcing Mariah Carey ... yet he's turned her into Jesus Christ.

Cannon was at Playhouse in Hollywood Thursday night to celebrate his birthday. As celebs are known to do, Nick took off his shirt at one point and revealed the massive new ink.

It's hard to make out the details from the photo, but our Nick sources say the tattoo shows Jesus on the cross with angel wings coming off the end the cross.

And in the smoke department ... Amber Rose was there.