1 Corinthians 9:23

And I do all things for the gospel's sake, that I may be a joint partaker thereof. [He made every sacrifice for the success of the gospel, that he might share with other successful apostles and evangelists in its triumphs and blessings (John 4:36). He recommends to others a like spirit of abstinence and sacrifice, and to illustrate the necessity and utility of such a course he draws some comparisons between those who run the Christian race, and the athletes who competed for the prizes in the Grecian games. The Corinthians were familiar with the ways and customs of these athletes, for one of the great race-courses lay in the immediate vicinity of Corinth, and at this time it was the most noted in Greece, having even surpassed the Olympic in its popularity. It was held triennially. Parts of its stadium are still seen as one goes from Corinth to Athens.]