1 Corinthians 9:16-27
16 For though I preach the gospel, I have nothing to glory of: for necessity is laid upon me; yea, woe is unto me, if I preach not the gospel!
17 For if I do this thing willingly, I have a reward: but if against my will, a dispensation of the gospel is committed unto me.
18 What is my reward then? Verily that, when I preach the gospel, I may make the gospel of Christ without charge, that I abuse not my power in the gospel.
19 For though I be free from all men, yet have I made myself servant unto all, that I might gain the more.
20 And unto the Jews I became as a Jew, that I might gain the Jews; to them that are under the law, as under the law, that I might gain them that are under the law;
21 To them that are without law, as without law, (being not without law to God, but under the law to Christ,) that I might gain them that are without law.
22 To the weak became I as weak, that I might gain the weak: I am made all things to all men, that I might by all means save some.
23 And this I do for the gospel's sake, that I might be partaker thereof with you.
24 Know ye not that they which run in a race run all, but one receiveth the prize? So run, that ye may obtain.
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.
26 I therefore so run, not as uncertainly; so fight I, not as one that beateth the air:
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.
The Grace New Testament Commentary - 1 Corinthians 9:24-27
9:24-27 He offers strong practical application for believers to engage in discipline in light of winning others to Christ, and he uses himself and the Corinthians' own Isthmian athletic games as examples. He refers to particular events of running and boxing that were part of these Isthmian games, which were close to the city of Corinth. The athlete took ten months to train for these games. In these games all the runners prepare to run, but in the actual event only one receives the prize (brabeion). Paul exhorts the church in Corinth to run in such a way that [they] may obtain the prize. He continues that everyone who competes for the prize is temperate in all things. The verb agonizomai (competes) means "to get in shape in order to participate in the games." The word "agony" comes from it. Temperate refers to the athlete's self-control because of this strict training. The athletes in the Isthmian games exercised discipline so that when they would come to their event they would win it and obtain a perishable crown. The word crown (stephanos) was a wreath woven of oak, ivy, or spruce, which was given to the victor.
All believers are given this same opportunity to win an imperishable crown. An imperishable crown, awarded by the King of kings, is far more valuable than a perishable one awarded by some local official. Furthermore Christians are not competing against one another in the "race" or in the "event." They are competing against themselves. In the Isthmian games only one person wins, but in the Christian race all who abide by the rules and run the race with diligence receive this imperishable crown (cf. 2 Tim 2:5). The athlete would receive a wreath that would eventually fade and fall apart. But the faithful believer receives a crown that lasts forever. It does not fade or fall apart.
Paul is not telling the unsaved that they need to run the race in order to earn eternal life. Rather he is addressing the believers who have been given the gift of eternal life, and he is telling them they can win a prize for the faithful discipline in their lives. He offers himself as an example of this when he says, Therefore I run thus: not with uncertainty. He stays on course and does not run aimlessly. He also engages in the boxing match not as one who beats the air. It would be futile for a boxer to punch the air.
Paul realizes that his greatest problem in this contest is himself. So he disciplines his body (cf. Rom 7:24; 8:8, 10-11) so that he will not become disqualified (adokimos, lit., disapproved; cf. 2 Tim 2:15 which has dokimos, "approved"). The apostle did not fear the loss of eternal life. He feared not having His Lord's approval at the Judgment Seat of Christ, and not having the privilege of ruling with Christ which will come to all who have His approval (cf. Luke 19:17: 1 Cor 9:25).