How do we know that repentance leads to forgiveness?

The assurance of forgiveness upon repentance is grounded in God's nature and the redemptive work of Christ. For instance, in Psalm 51, David appeals to God's steadfast love and abundance of mercy as the basis for his plea for forgiveness. Additionally, 1 John 1:9 explicitly states that if we confess our sins, He is faithful and just to forgive us. This underscores the covenantal nature of God's mercy, where repentance is a necessary response to sin but is entirely rooted in the grace extended to us through Jesus' sacrificial death. Thus, we can be confident that sincere repentance aligns with God's promise to forgive those who come to Him in faith.