Chapter 9 illustrates the principle of chapter 8: love may set aside its rights for others. Paul first establishes that he has rights. He is an apostle who has seen the risen Lord, and the Corinthian church is the seal of his apostleship. Soldiers do not serve at their own expense, farmers eat from their vineyards, and priests share in the altar's offerings. The Lord himself ordained that those who proclaim the Good News should live from it.
Nevertheless, Paul refused to use this right among them. He would rather die than lose his boast of preaching without charge. For him, preaching is not optional; necessity is laid on him. His reward is to offer the Good News free of charge. Though free from all, he made himself a slave to all. He adapted himself to Jews and Gentiles, to those under the law and those outside it, and to the weak, becoming all things to all people that by all means he might save some.
Paul ends with a picture of runners in a race and a boxer (9:24-27). Athletes exercised rigorous self-control for a perishable wreath. Believers pursue an incorruptible one. Paul does not run aimlessly or box at the air. He disciplines himself so that, after preaching to others, he himself will not be disqualified. Flexibility in method is joined to firmness in devotion.