Gen 3:15, 22:17-18, 26:4, 28:13-14, Gal 3:16
God is the God of the covenant who made the covenant with Abraham, Isaac, and Jacob. (Ex 3:6)
Ex 3:6 Moreover he said, I am the God of thy father, the God of Abraham, the God of Isaac, and the God of Jacob. And Moses hid his face; for he was afraid to look upon God.
God promised to send Christ to the first man, Adam. (Genesis 3:15)
Genesis 3:15 And I will put enmity between thee and the woman, and between thy seed and her seed; it shall bruise thy head, and thou shalt bruise his heel.
God promised Abraham, Isaac, and Jacob that he would send Christ as their descendant. (Gen 22:17-18, Gen 26:4, Gen 28:13-14)
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;
Gen 28:13 And, behold, the Lord stood above it, and said, I am the Lord God of Abraham thy father, and the God of Isaac: the land whereon thou liest, to thee will I give it, and to thy seed; 14 And thy seed shall be as the dust of the earth, and thou shalt spread abroad to the west, and to the east, and to the north, and to the south: and in thee and in thy seed shall all the families of the earth be blessed.
Jesus is the Christ God promised to Abraham and his descendants. (Gal. 3:16)
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.