1 Corinthians 9 : 15 But I have used none of these things: neither have I written these things, that it should be so done unto me: for it were better for me to die, than that any man should make my glorying void. 16 For though I preach the gospel, I have nothing to glory of: for necessity is laid upon me; yea, woe is unto me, if I preach not the gospel!

Paul in theses verses is letting the the people know that he was not in this for the gain he could get out of it but that he wanted them to understand they needed to take care of those that followed after him. He was called by the Lord Jesus Christ to minister and he would not let anything hinder him from doing that. His desire was to do the will of  god and he learned to be content in the good times and bad. Paul goes on to say that he has noting to brag about because he was compelled to preach gospel ans the Damascus road experience. He thought before that experience he was doing the will of God, but he was not fully informed,  and now he is so he has dedicated the rest of his life to preach the good news of Jesus Christ. He winds these up with saying woe to those that who are unfaithful in their ministering. This helps us to see we need to faithful in ministering and be glad we can do this whether we get any reward here on this earth for it or not, but just be glad we have the opportunity to spread the gospel.