Verse 1 is not an abrupt change of subject but a continuation of the same subject, as shown by 1 Corinthians 10:23-26, which talks about conscience and the eating of meat offered to idols from another standpoint. Therefore, chapter 9 is a parenthetical thought of the principle of not using our liberties indiscriminately. Paul was momentarily digressing on the importance of considering the conscience of others. Our liberties must be curbed at times if we would become members of the Little Flock.
Why did Paul ask this question? His personal sacrifice and behavior were another evidence of his faithfulness and apostleship. He curbed his personal liberties, even though he had “power to eat and to drink.” His behavior was obviously different from that of the others in that he greatly restricted himself. With regard to meat and drink, he was very careful not to offend anyone. If any of the Corinthians were awake, they should have noticed that Paul was sacrificing a lot in order to enhance his message. Even if they differed with him in doctrine, they should have respected his desire to serve and please God. As Jesus said, “If you cannot accept my teachings, at least appreciate the works that I am doing” (John 10:25,38; 14:11 paraphrase). If the Jews accepted Jesus’ works, then maybe later on, they would also accept his teachings. He was trying to reach through the barrier of Jewish prejudice and training. The Apostle Paul was speaking similarly here, and the Corinthians should have observed his deeds.