The New Testament reveals that Christ in His humanity is the seed of Abraham (Matt. 1:1). This was prophesied in such places as Genesis 17:8 and 22:18. In Galatians 3:16 Paul emphasizes that Christ is the fulfillment of the prophecies in Genesis concerning the seed of Abraham: “To Abraham were the promises spoken and to his seed. He does not say, And to the seeds, as concerning many, but as concerning one: ‘And to your seed,’ who is Christ.” Here Paul indicates that in God’s eyes Abraham has only one seed, that is, Christ. As the seed of Abraham, Christ is typified by Isaac, who came out of Abraham and received the inheritance. Furthermore, Christ in His humanity blesses the nations so that the nations may receive the gospel of Christ, which is to receive the Spirit promised by God (v. 14).
Christ as the seed of Abraham in His humanity is typified by Isaac (Matt. 1:2). Jehovah God promised to give the land of Canaan to Abraham and to his seed as an eternal possession (Gen. 17:8), and He said that the nations on the earth would be blessed because of Abraham’s seed (22:18). Nevertheless, the seed that God referred to was not many people, but one person. Paul pointed out in Galatians that this one is Christ, not Isaac. As far as Abraham was concerned the “seed” was Isaac. According to Galatians 3:16, in the eyes of God the “seed” who would receive the inheritance and bless the nations is Christ. Isaac is a figure of the coming Christ, and the reality is Christ. Christ in His humanity is the unique seed of Abraham; He is the seed that inherits the promise. In order to inherit the promised blessing, we must be one with Christ. Outside of Him we absolutely cannot inherit the God-promised blessing. We must be in Christ through faith in order to partake of all the promises God that gave to Abraham (vv. 7-9).
In Galatians 3:14 Paul says, “In order that the blessing of Abraham might come to the Gentiles in Christ Jesus, that we might receive the promise of the Spirit through faith.” This indicates that Christ in His humanity is the seed of Abraham so that the nations can receive the gospel of Christ, which is the blessing God gave to Abraham (Gen. 22:18; Gal. 3:8-12). Christ is not only the unique seed who inherits the promise as typified by Isaac; He is also the promise of blessing to be received by man. When Jehovah God appeared to Abraham, He promised to give him two things—the good land and the seed, both of which typify Christ. This means that in type, God was giving Christ to Abraham as the good land and the seed. According to Paul’s interpretation in Galatians 3, both the good land and the seed are the Spirit. The blessing of the gospel is the promised Spirit. The physical aspect of this blessing that God promised to Abraham is the good land (Gen. 12:7; 13:15; 17:8; 26:3-4), which is a type of the all-inclusive Christ (cf. Col. 1:12). Since Christ in His humanity is eventually realized as the all-inclusive life-giving Spirit (1 Cor. 15:45b; 2 Cor. 3:17) by the New Testament believers, this allinclusive life-giving Spirit is the blessing promised to Abraham.
Matthew reveals that Christ as a man in His humanity is the seed of David (1:1; 22:42-45). This fulfilled the prophecy spoken by the prophet Nathan to David in 2 Samuel 7:12-14a: “When your days are fulfilled and you sleep with your fathers, I will raise up your seed after you, which will come forth from your body, and I will establish his kingdom. It is he who will build a house for My name, and I will establish the throne of his kingdom forever. I will be his Father, and he will be My son.” In this prophecy we see that God would raise up a seed for David and would also establish His kingdom forever. The fulfillment of this is referred to in Revelation 11:15, which says that Christ “will reign forever and ever.”
This prophecy in 2 Samuel 7 says that the seed of David would become the Son of God, and God would be His Father. In other words, a human seed would become the divine Son. In Romans 1:3-4 this prophecy is explained fully: “Concerning His Son, who came out of the seed of David according to the flesh, who was designated the Son of God in power according to the Spirit of holiness out of the resurrection of the dead, Jesus Christ our Lord.” This indicates that Christ in His humanity is the seed of David and that in resurrection His humanity was sanctified, uplifted, transformed, and designated the Son of God.