'Truth of the Gospel' in the Bible

But we did not give up and submit to these people for even an hour, so that the truth of the gospel would be preserved for you.

But when I saw that they were deviating from the truth of the gospel, I told Cephas in front of everyone, “If you, who are a Jew, live like a Gentile and not like a Jew, how can you compel Gentiles to live like Jews?”