Jacob valued the birthright Gen 25:31-33. For that reason the Lord chose Jacob`s lineage to be His lineage.
Those who value the birthright that Christ Jesus has willed to them, become a chosen, peculiar people unto himself.
Genetic calling was never in the Lord`s mind. We are all genetic descendents of Adam. The Lord called Abram and Abram responded in faith Rom 4:3.
The descendents of Jacob can only be saved the same way gentiles are saved - by GraceThroughFaith InChrist Jesus.
To believe otherwise nullifies the shed blood of Jesus and makes Him out to be unjust Act 10:34 1Pe 1:17.
Believers in Christ Jesus are the true children of Abraham Gal 3:7.