You're a descendant of Jacob. I'm a descendant of Jacob. Keras is a descendant of Jacob. You don't have to be a genetic descendant to be the house of Israel:
Genesis 48:19 And Joseph's father, Jacob, refused and said, `I know, my son, I know, Manasseh also shall become a people, and he also is great, and yet, his young brother, Ephraim, is greater than he, and his seed is the fullness of the Gentiles'.
The House of Israel, the Northern Kingdom, is collectively called 'Ephraim' in many Biblical prophecies referring to their destiny - and Paul said,
Romans 9:25-26 As He also says in Hosea, "I will call those not My people, My people; and those not beloved, Beloved". And it shall be, in the place where it was said to them. "You are not My people"; there they shall be called "sons of the living God."
In their Old Testament Biblical context, those verses are referring to the house of Israel, yet here in Romans they are applied to Gentiles who believe in Jesus. Why?
Hosea 1:11 "Then the sons of Judah and the sons of Israel shall be gathered together, and shall set over themselves one head, and they shall come up out of the land. For great shall be the day of Jezreel.
The Kingdom of Christ belongs to Christ and to His people. Who are His people?
Galatians 3:28-29 There is not here Jew or Greek, there is not here servant nor freeman, there is not here male and female, for all ye are one in Christ Jesus; and if ye are of Christ then of Abraham ye are seed, and according to promise--heirs.