1 Corinthians 9:24-27

have ye not known that those running in a race — all indeed run, but one doth receive the prize? so run ye, that ye may obtain; and every one who is striving, is in all things temperate; these, indeed, then, that a corruptible crown they may receive, but we an incorruptible; I, therefore, thus run, not as uncertainly, thus I fight, as not beating air; but I chastise my body, and bring [it] into servitude, lest by any means, having preached to others — I myself may become disapproved.