One of the resources I was looking at kind of helped me understand Romans 9 a little better. The resource said, “Israel’s unbelief reflects the mystery of the divine election that is always operative within it. Mere natural descent from Abraham does not ensure the full possession of the divine gifts; it is God’s sovereign prerogative to bestow this fullness upon, or to withhold it from, whomsoever he wishes.” So ultimately, it is the faith that matters, not the luck of the draw (ie being born in Abraham’s lineage). The below scripture seems to illustrate the idea that the decision is up to God:

10 This son was our ancestor Isaac. When he married Rebekah, she gave birth to twins.[f] 11 But before they were born, before they had done anything good or bad, she received a message from God. (This message shows that God chooses people according to his own purposes; 12 he calls people, but not according to their good or bad works.) She was told, “Your older son will serve your younger son.”[g] 13 In the words of the Scriptures, “I loved Jacob, but I rejected Esau.”[h]
14 Are we saying, then, that God was unfair? Of course not! 15 For God said to Moses,
“I will show mercy to anyone I choose, and I will show compassion to anyone I choose.”[i]
16 So it is God who decides to show mercy. We can neither choose it nor work for it.
17 For the Scriptures say that God told Pharaoh, “I have appointed you for the very purpose of displaying my power in you and to spread my fame throughout the earth.”[j] 18 So you see, God chooses to show mercy to some, and he chooses to harden the hearts of others so they refuse to listen.

This just reminds me of how immature I really am. I can identify with the Jews who thought, “Well, I am in the line of Abraham, therefore… “or “I am the first born, therefore…” or whatever it was that they felt entitled to as a result of custom and tradition. That makes me think of the customs and traditions that I hold to in my own life that I somehow think (maybe I don’t articulate it) that these customs and traditions trump the mystery of God’s will. I need to find those traditions and discard them because ultimately, only God’s will matters.