How do we know the promise of forgiveness is true?

The assurance of the promise of forgiveness is established through both scripture and the historical life of Jesus Christ. Throughout the Old Testament, prophecy prepares for a Savior who would come to redeem His people. Zechariah 13:1 emphasizes a fountain opened for the people, revealing God's plan of salvation well before Christ’s incarnation. This promise was fulfilled in Jesus, who, through His sacrifice, atones for sin once and for all, thus ensuring that the forgiveness offered is not just theoretical but a historical truth established in the gospel.