Here's something you've never seen before ... Tim Tebow got dominated in a push-up battle -- all while he was spending time with inmates at a Texas prison!!!
Tim -- who's been preaching religion to people behind bars for YEARS -- visited the Alfred D. Hughes Unit in Gatesville, TX on Thursday to talk with the guys.
But, at some point ... Tim put down the mic and put his arms to the test -- 'cause the ex-NFL QB went one-on-one with an inmate in a push-up contest ... and got DESTROYED!!!
The former Heisman Trophy winner actually threw up some amazing numbers .