Paul defends himself against some who have cast doubt on his apostleship. He points to the fact that he has seen Jesus. He argues that the Corinthian church would not exist without his ministry as an apostle, because he brought the gospel to them. It seems that some people were questioning his apostleship because Paul did not take financial support for his ministry. Paul explains that it is very proper and right for ministers of the gospel to be paid for their ministry, just as a soldier expects pay, a vintner eats his own grapes, and a shepherd takes milk from his flock. This is common sense. Even the Old Testament Law affirms this, declaring that no one should muzzle an ox while it works, so that it can eat and replenish its strength. Thus, ministers of the gospel have the right to be paid for their ministry.
But Paul does not take advantage of that right; instead, he works a job to pay for his own ministry. He does not want to hurt his witness by having other men give him money to preach, but would rather offer the gospel without expectation of monetary reward. Paul serves all men, Jews and Greeks, and meets them where they are so that they might believe in the gospel of Jesus. He runs the race of life like an athlete, denying himself comfort so that he can focus on serving Jesus at his very best, like a runner who trains to win the race. To be financially supported by other men would tempt Paul to serve their interests, or to abuse his power as an apostle, so he denies himself this right. He does not want to fail to win the race of life. To win the race of life is to do all God asks of us. In Paul’s case that is to take the gospel to the Gentiles. He urges the Corinthians to likewise run the race to win. His hope is to earn the ultimate prize from Jesus in reward for obedience.