How do we know God chooses whom He will save?

In Romans 9:11-12, Paul notes that God's choice of Jacob over Esau was made before either had done good or evil, underscoring that God's election is based solely on His will. This highlights the notion that God's grace cannot be earned through works but is a sovereign act of mercy. Moreover, throughout Scripture, God reveals His prerogative to choose, emphasizing that salvation is only by His grace and not based on human lineage or effort. This divine selection is a key tenet of the Reformed faith, correlating with the belief in the unconditional election component of TULIP.