How do we know that God chooses who will be saved?

The doctrine of divine election is clearly illustrated in several scriptures, including John 17, where Jesus emphasizes that he is praying specifically for those the Father has given him. This reflects the Reformed theology that salvation is initiated by God's sovereign will, as supported by Ephesians 1:4-5, which details how God chose believers before the foundation of the world. Furthermore, 2 Thessalonians 2:13 underscores that salvation is through sanctification of the Spirit and belief in the truth, highlighting God's active role in choosing individuals for salvation.