This chapter is best understood as a continuation of the previous one. In chapter 8 Paul explained that believers must be willing to relinquish their rights so as not to offend less mature brothers and sisters in Christ. In this chapter Paul shares specific ways he had refrained from some things he had the right to do, yet could be used as an obstacle to people receiving his ministry and believing the gospel.
As an apostle of Jesus, Paul had the right and authority to demand that the churches he planted show him hospitality and take care of all his needs. Instead, Paul worked (he was a tent maker) to earn his own living so that he could “present the gospel free of charge” (v.18). That way, no one could ever accuse him of preaching just for money. It is interesting that Paul presented a water-tight argument for the fact that churches should support their pastors with fair and adequate pay, but then refused it himself (v.6-15). I think he did this because he was more concerned with reaching people for Christ than getting what he deserved. Paul’s attitude is an enduring example of exercising discipline instead of freedom.
Corinth was the home to the famous Isthmian Games (affiliated with the ancient Olympics), so the believers there would have been familiar with the strict training regimen of top athletes. Paul disciplined himself like an athlete, and athletes have to say “no” to things others say “yes” to — all so that they will be ready to compete for the prize. Isthmian champions competed for a wreath of leaves, but for Paul (and all believers) the stakes were much higher: the souls of men and women hung in the balance. That is why the spiritual disciplines of prayer, Bible study, worship, and ministry are so important for us. When we diligently attend to these disciplines every day, we remain sharp and ready for any assignment God may give us. No wonder Paul made such an impact for Jesus — he was careful, purposeful, and faithful about his responsibilities as disciple.