Galatians 6:16

And as many as walk according to this rule. The rule laid down by S. Paul as to justification, and the relation of Judaism to Christianity.

Peace be on them, and mercy, and upon the Israel of God. On Jews and Gentiles alike who believe on Christ, according to Ambrose; but comparing this verse with Eph 1:1 and Colossians 2:8, it is better to explain the Israel of God as those who are Israelites indeed, i.e., who have embraced Christianity and renounced whether Gentilism or Judaism. Not those who are descended from Jacob according to the flesh are the Israel of God, but those who have embraced his faith. These find peace within, and on them God plentifully bestows His grace.

There may be a reference to the meaning of Israel, i.e., he who sees God, says Theophylact. They who see Him by faith here will see Him under a fitting image in heaven. Or Israel may mean "he who has power with God," according to Genesis 32:28. As Jacob by his prayers obtained success against Esau, so the people of God are by His grace masters over the world and all its lusts, and over Judaism. So S. Thomas and Haymo.