1 Corinthians 9:24-27

9:24 Know ye not that they which run in a race run all, but one receiveth the prize? So run, that ye may obtain.

9:25 And every man that striveth for the mastery is temperate in all things. Now they do it to obtain a corruptible crown; but we an incorruptible.

9:26 I therefore so run, not as uncertainly; so fight I, not as one that beateth the air:

9:27 But I keep under my body, and bring it into subjection: lest that by any means, when I have preached to others, I myself should be a castaway.

King James Bible (1611)