Manti Te'o is adamant his football career is over ... telling TMZ Sports his purpose in life is now to help other people -- not crack running backs on a gridiron anymore.
The former linebacker made the revelation to us out at LAX ... saying he's officially hung up his spikes at 32 years old.
"I'm playing a different game now," the Notre Dame legend said. "I'm trying to empower people. Trying to inspire people. That's the game that I'm playing now, and I'm trying to be the best at that.