9:18. What is my reward then? That preaching the gospel, I may deliver the gospel without charge, that I abuse not my power in the gospel.
9:19. For whereas I was free as to all, I made myself the servant of all, that I might gain the more.
9:20. And I became to the Jews a Jew, that I might gain the Jews:
9:22. To the weak I became weak, that I might gain the weak. I became all things to all men, that I might save all.
9:23. And I do all things for the gospel's sake, that I may be made partaker thereof.
9:24. Know you not that they that run in the race, all run indeed, but one receiveth the prize. So run that you may obtain.
9:25. And every one that striveth for the mastery refraineth himself from all things. And they indeed that they may receive a corruptible crown: but we an incorruptible one.
9:26. I therefore so run, not as at an uncertainty: I so fight, not as one beating the air.
9:27. But I chastise my body and bring it into subjection: lest perhaps, when I have preached to others, I myself should become a castaway.
I chastise, etc… Here St. Paul shews the necessity of self-denial and mortification, to subdue the flesh, and its inordinate desires.