How do we know that God has chosen some for salvation?

The doctrine of election asserts that God sovereignly chooses individuals for salvation, a truth supported by scriptures like Romans 9:16: 'It is not of him that willeth, nor of him that runneth, but of God that sheweth mercy.' This emphasizes that salvation is not based on human effort or merit, but solely upon God's mercy and good pleasure. Furthermore, 1 Thessalonians 5:9 states that God has not appointed us to wrath, thus affirming that some are chosen for salvation, highlighting His purpose and grace throughout Scripture.