1 Corinthians 9:24-27

24Know ye not that they who run in a race all run, but one receiveth the prize? So run, that ye may obtain. 25And 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. 26I therefore so run, not as uncertainly; so I fight, not as one that beateth the air: 27But I keep under my body, and bring it into subjection: lest by any means, when I have preached to others, I myself should be a castaway.