Римлянам 1:2

Which he had promised afore . . . in the holy scriptures--Though the Roman Church was Gentile by nation (see on Rom 1:13), yet as it consisted mostly of proselytes to the Jewish faith (see on Introduction to this Epistle), they are here reminded that in embracing Christ they had not cast off, but only the more profoundly yielded themselves to, Moses and the prophets (Act 13:32-33).

In this chapter we may observe, I. The preface and introduction to the whole epistle, to Rom 1:16. II. A description of the deplorable condition of the Gentile world, which begins the proof of the doctrine of justification by faith, here laid down at Rom 1:17. The first is according to the then usual formality of a letter, but intermixed with very excellent and savoury expressions.