1 Corinthians 4:15; 1 Corinthians 9:12; 1 Corinthians 9:14; 1 Corinthians 9:18; 1 Corinthians 9:23; 1 Corinthians 15:1

15 For if you were to have countless tutors in Christ, yet you would not have many fathers, for in Christ Jesus I became your father through the gospel.
12 If others share the right over you, do we not more? Nevertheless, we did not use this right, but we endure all things so that we will cause no hindrance to the gospel of Christ.
14 So also the Lord directed those who proclaim the gospel to get their living from the gospel.
18 What then is my reward? That, when I preach the gospel, I may offer the gospel without charge, so as not to make full use of my right in the gospel.
23 I do all things for the sake of the gospel, so that I may become a fellow partaker of it.
1 Now I make known to you, brethren, the gospel which I preached to you, which also you received, in which also you stand,