Romans 1:1-4, What is the Gospel?
Romans 1:1-4 Paul, a servant of Jesus Christ, called to be an apostle, separated unto the gospel of God, 2 (Which he had promised afore by his prophets in the holy scriptures,) 3 Concerning his Son Jesus Christ our Lord, which was made of the seed of David according to the flesh; 4 And declared to be the Son of God with power, according to the spirit of holiness, by the resurrection from the dead:
The gospel message was first published by the written testimony of the prophets in the Old Testament consisting of 5 books of the Law (Genesis to Deuteronomy), 12 historical books (Joshua to Esther), 5 wisdom books (Job to Son of Solomon), 5 books of Major Prophets (Isaiah to Daniel) and 12 books of the Minor Prophets (Hosea to Malachi). The theme was concerning God’s Son Jesus Christ.
Jesus confirmed this in Luke 24:44 And he said unto them, These are the words which I spake unto you, while I was yet with you, that all things must be fulfilled, which were written in the law of Moses, and in the prophets, and in the psalms, concerning me.