How do we know God saves sinners according to the Bible?

The assurance of God's saving work is found throughout Scripture, particularly in the New Testament, where it is revealed that salvation comes through Jesus Christ. For example, in 2 Corinthians 4:3-6, Paul explains that God, who commanded light to shine out of darkness, has shone in our hearts to give us the knowledge of His glory in Christ. This implies that salvation is wholly dependent on God's sovereign grace, as He alone brings light to the darkness of our hearts, enabling us to see our need for redemption. Additionally, the sacrifice of Jesus, who bore our sins to reconcile us with the Father, is the central theme of the Gospel.