Romans 2:26

Therefore if the uncircumcision keep the . . . law, &c.--Two mistaken interpretations, we think, are given of these words: First, that the case here supposed is an impossible one, and put merely for illustration [HALDANE, CHALMERS, HODGE]; second that it is the case of the heathen who may and do please God when they act, as has been and is done, up to the light of nature [GROTIUS, OLSHAUSEN, &c.]. The first interpretation is, in our judgment, unnatural; the second, opposed to the apostle's own teaching. But the case here put is, we think, such as that of Cornelius (Acts 10:1-48), who, though outside the external pale of God's covenant, yet having come to the knowledge of the truths contained in it, do manifest the grace of the covenant without the seal of it, and exemplify the character and walk of Abraham's children, though not called by the name of Abraham. Thus, this is but another way of announcing that God was about to show the insufficiency of the mere badge of the Abrahamic covenant, by calling from among the Gentiles a seed of Abraham that had never received the seal of circumcision (see on Gal 5:6); and this interpretation is confirmed by all that follows.

The scope of the first two chapters of this epistle may be gathered from Rom 3:9, "We have before proved both Jews and Gentiles that they are all under sin." This we have proved upon the Gentiles (ch. 1), now in this chapter he proves it upon the Jews, as appears by Rom 2:17, "thou art called a Jew." I. He proves in general that Jews and Gentiles stand upon the same level before the justice of God, to Rom 2:11. II. He shows more particularly what sins the Jews were guilty of, notwithstanding their profession and vain pretensions (Rom 2:17 to the end).

2:26 won’t God declare them to be his own people? Paul might be speaking of Gentile Christians who are God’s people because they obey God’s law, or he could be speaking hypothetically about what would happen if a Gentile perfectly obeyed God’s law.