There is one salvation, not two. There is not a Jewish salvation and a Gentile salvation, a Jewish kingdom and a Gentile kingdom, a Jewish bride and a Gentile bride, a Jewish church and a Gentile church. The Divine salvation is in the Lord Jesus Christ and in those who have been made an eternal part of Him.
The true salvation is one progressive revelation of God. There indeed has been a change of covenant. However, both the old covenant and the new covenant were made with the one elect—God’s Israel, whether Jewish or Gentile by physical birth. The old covenant was written on stone and the new covenant is written on the heart. The two covenants require righteousness, holiness, and obedience on the part of Israel and on the part of all who would partake of the salvation of the Lord.
