For killing his brother Abel, Cain, the firstborn, is passed over in favour of Seth, the third-born (Gen 4:1-25).
Ismael is Abraham’s firstborn, but he is excluded because he is the son of Sarah’s Egyptian maidservant (Gen 16:1-61; 17:18-21; 21:9-21).
And Esau sells his birthright (Gen 25:29-34) and displeases his parents by wrong married choices (Gen 26:34-35).
Then, Jacob blesses Joseph’s two sons Manasseh and Ephraim by placing the younger over the older (Gen 48:1-22).
But, Gen 38 also speaks about Judah’ lineage - and that must be something to it (Gen 49:8-10).
The first leader of Israel, Joshua, comes from the line of Ephraim (Num 13:8).
Then the first king comes from the tribe of Benjamin (1 Sam 9:1-2).
Finally, both lines were replaced by Judah (Ps 78:59-72).
Those chosen people by God are never perfect
Noah (Gen 9:20-21);
Abraham (Gen 12:10-13);
Jacob (Gen 27:1-40).
But, although Jesus comes from the royal line of Abraham and David, the Bible states that he is:
Greater than Abraham (John 8:52-58)
Greater than David (Mt 22:41-46)
Greater than Solomon (Mt 12:42)
The “seed” of Abraham should resemble him in faith/trust in God (Gal 3:6-7; Rom 4:16-17).
The true children of Abraham are those who, like Abraham, exercise faith.