How do we know that God's promises are not void?

In Romans 9, Paul addresses the concern that God's promises may be voided by the rejection of Israel. He clarifies that the physical descendants of Abraham are not the only ones who are truly regarded as Israel; rather, it is the spiritual Israel, chosen by God, that truly fulfills His promises. The integrity of God’s promises is maintained through His election, which ensures that every individual elected to salvation will inevitably come to faith. Therefore, His declarations regarding salvation remain intact and effective.