Why do people have a hard time comprehending the gospel of grace?
People have a hard time comprehending the gospel of grace because elements not belonging to it are added, producing confusion. Scripture shows Peter and Barnabas not walking uprightly according to the truth of the gospel, because grace had set people free from the Law, yet Gentiles were still being compelled to live as Jews.
Les explains that the issue is not new. In the context, Peter, Barnabas, and other Jews were not walking uprightly according to the truth of the gospel. The speaker confronts Peter, asking why, if he lives after the manner of Gentiles and admits that the grace of God has set people free from the Law, he still compels Gentiles to live as Jews. Les says it is no different today: the rhetoric may differ, but the concept is the same. People add things that do not belong to the gospel of grace, then wonder why others have a hard time comprehending it. The result is confusion.
But when I saw that they walked not uprightly according to the truth of the gospel, I said unto Peter before them all, If thou, being a Jew, livest after the manner of Gentiles, and not as do the Jews, why compellest thou the Gentiles to live as do the Jews?