Definition of "deen"

Sterling was Muslim, and although he wasn't on his deen, Shanice and Shakira felt that he should have had a Janazah.

2014, CHANEL, Purple Ink Presents Savage Sisters by Chanel, iUniverse

You say you're Muslim, you say you're Rasta / Say you don't eat pork, don't eat pussy / Liar, you're just an actor / Blud, you're not on your deen

2016, Skepta, Shutdown, on Konnichiwa