1 Corinthians 9:19

For though I was free from all men [and therefore had a right to demand wages of them and ignore their prejudices], I brought myself under bondage to all, that I might gain the more. [Here was yet another joy which he found in preaching a free gospel. His spirit of self-sacrifice won the confidence of the people, and enabled him to make a larger number of converts. Though entitled to wages as a free man he preferred to work as a slave for nothing, accounting the additional disciples which he thus made as a more acceptable hire than his maintenance. Moreover, after the manner of a slave, he had adjusted himself to the prejudices and idiosyncrasies of each class which he served as far as he innocently could; that, by having a larger measure of their confidence and good-will, he might be able to win a larger number to Christ. He now describes this part of his service.]