1 Corinthians 9:24-27 - The Need For Self-Discipline
24 Know ye not that they who run on the course, all run indeed, yet but one obtaineth the price? So run, that ye may obtain. 25 And every one who contendeth [in the games] is temperate in all things: they indeed therefore do it that they may receive a corruptible crown, but we an incorruptible. 26 I therefore so run not as uncertainly; so do I exercise with my fists, not as striking the air: 27 but I beat down my body, and bring it into subjection, that I may not by any means, after having preached to others, myself become reprobate.