Gen 22:17-18, Gen 26:4, Gal 3:16, Lk 1:72-80

In the Old Testament, God promised to send Christ, an eternal promise to Abraham and his descendants. (Psalms 105:8-11, Gen 22:17-18, Gen 26:4, Gal 3:16)

Psalms 105:8 He hath remembered his covenant for ever, the word which he commanded to a thousand generations. 9 Which covenant he made with Abraham, and his oath unto Isaac; 10 And confirmed the same unto Jacob for a law, and to Israel for an everlasting covenant: 11 Saying, Unto thee will I give the land of Canaan, the lot of your inheritance:

Gen 22:17 That in blessing I will bless thee, and in multiplying I will multiply thy seed as the stars of the heaven, and as the sand which is upon the sea shore; and thy seed shall possess the gate of his enemies; 18 And in thy seed shall all the nations of the earth be blessed; because thou hast obeyed my voice.

Gen 26:4 And I will make thy seed to multiply as the stars of heaven, and will give unto thy seed all these countries; and in thy seed shall all the nations of the earth be blessed;

Gal 3:16 Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ.

The Christ promised by God to Abraham and his descendants has come to this earth. That is Jesus. And John the Baptist prepared the way for Christ. (Luke 1:72-80, Matthew 1:16)

Matthew 1:16 And Jacob begat Joseph the husband of Mary, of whom was born Jesus, who is called Christ.

Luke 1:72 To perform the mercy promised to our fathers, and to remember his holy covenant; 73 The oath which he sware to our father Abraham, 74 That he would grant unto us, that we being delivered out of the hand of our enemies might serve him without fear, 75 In holiness and righteousness before him, all the days of our life. 76 And thou, child, shalt be called the prophet of the Highest: for thou shalt go before the face of the Lord to prepare his ways; 77 To give knowledge of salvation unto his people by the remission of their sins, 78 Through the tender mercy of our God; whereby the dayspring from on high hath visited us, 79 To give light to them that sit in darkness and in the shadow of death, to guide our feet into the way of peace. 80 And the child grew, and waxed strong in spirit, and was in the deserts till the day of his shewing unto Israel.