Romans 9

Though much of Paul's writings to the Romans are difficult for me to understand, I feel it is clear his truthful statement -

"Who are Israelites; to whom pertaineth the adoption, and the glory, and the covenants, and the giving of the law, and the service of God, and the promises;
5 Whose are the fathers, and of whom as concerning the flesh Christ came, who is over all, God blessed for ever. Amen."  (Romans 9:4–5)

I feel the doctrine is that when we are faithful,  sealed by proper priesthood authority, sealed by the Holy Spirit of promise we become Israelites or the family of Israel and its associated promises of celestial glory.  As the family of Israel or of Christ, families can be together forever.