In all his conduct towards outsiders, Paul’s aim is to win them for Christ. This is the repeated claim of 1 Corinthians 9:19–22. Now he gives a further explanation of his motive. Not only does he want to win people for Christ, but he also wants to share with them
in the blessings of the gospel. The gospel itself demands a life of selfless service (Mark 8:34–38). Without selfless service to the gospel, one cannot expect to share in its blessings.
23 I do it all for the sake of the gospel, that I may share with them in its blessings.