Knicks Star J.R. Smith -- Ordered to Pay $48,000 ... You STOLE Black Jesus!

Don't mess with Black Jesus ... or YOU WILL PAY ... just ask Knicks stud J.R. Smith, whose ass just lost a $48,000 lawsuit involving a diamond necklace that features an Afro-American rendition of the Messiah.

A jewelry company called Lemmerman's sued Smith, claiming he ordered a bunch of bling back in 2010 -- including a diamond chain, two Black Jesus pendants and some earrings -- totaling $25,500 ... but never paid.

We're told one Jesus pendant and chain cost roughly $15,000 alone.

Lemmerman's sued for $48,101 -- which includes the jewelry bill plus interest and attorney's fees -- but Smith never responded to the suit ... so a judge ruled in Lemmerman's favor.

Smith has now been ordered to pay the $48,000 asap ... or else. Calls to Smith's people weren't returned.