Who promised the gospel beforehand through the prophets?
God promised the gospel beforehand through His prophets in the Holy Scriptures. That promise concerned His Son, Jesus Christ our Lord, who was made of the seed of David according to the flesh. The gospel was therefore not a new message; God had declared it beforehand through the prophets.
Les teaches that Paul was uniquely called of God to be the Apostle of the Gentiles—not one of many, but THE Apostle—and that Paul is the one to whom we must go for our basic doctrines. In the opening verses Paul was separated unto the Gospel of God, and in verse 2 Les explains that the “He” is God, who had promised that gospel before by His prophets in the Holy Scriptures. That promise concerned His Son, Jesus Christ our Lord, who was made of the seed of David according to the flesh. Les notes he could spend five years in Romans. The seed of David takes him back to Genesis 3:15, the seed of the woman, the promised line of redemption, that scarlet thread of salvation that starts with Genesis 3:15 and carries all the way through Scripture. He also connects it to the Abrahamic covenant in Genesis 12 and then Paul in Galatians.
(Which he had promised afore by his prophets in the holy scriptures,)
Concerning his Son Jesus Christ our Lord, which was made of the seed of David according to the flesh;