Gal 2:14 When I saw that they were not acting in line with the truth of the gospel, I said to Peter in front of them all, “You are a Jew, yet you live like a Gentile and not like a Jew. How is it, then, that you force Gentiles to follow Jewish customs?
In Galatians 2:14, Paul lays down a powerful principle. He deals with Peter’s racial pride and cowardice by declaring that he was not living “in line with the truth of the gospel”.
From this we see that the Christian life is a process of renewing every dimension of our life– spiritual, psychological, corporate, social–by thinking, hoping, and living out the “lines” or ramifications of the gospel. The gospel is to be applied to every area of thinking, feeling, relating, working, and behaving.The implications and applications of Galatians 2:14 are vast.
This is from Tim Kellers Centrality of the Gospel Document that can be found here: