“But we believe that we shall be saved through the grace of the Lord Jesus, in the same way as they.”
Whereas the truth as they now saw it in Jesus was that neither they nor the Gentiles would be saved by keeping the burden of the whole Law. Indeed as believing Christian Jews they believed that their salvation had come to them, and would one day in its full finality come to them, not through their Law-keeping but through the totally unmerited favour of the Lord, of Jesus. And they believed that the same would be true of believing Gentiles.
Indeed was that not what coming to Christ had meant for them all? They had come to Him because of their own shortcomings. They had come because they had ‘repented', because they had had a change of mind and heart about their sins and had wanted to be rid of them. They had come precisely because of their failure to ‘keep the Law'. And it was in Him, and through His grace, His unmerited lovingkindness and mercy, that they had received forgiveness for all their sins. That was how they had been made right with God. It was not through anything that they had done, but wholly through Him. How then could anything extra be asked of the Gentiles?
Thus Peter makes clear that, while he is content that Christian Jews still carry out the customs of their forefathers, he does not want them to see them as contributing towards their salvation. For all, whether Jewish Christian or Gentile Christian, their dependence is to be totally on ‘the grace of the Lord Jesus' which has provided the means of salvation through His cross, a salvation which is enjoyed by faith. To take any other attitude is to ‘fall away from grace' (Galatians 5:4).