How do we know the message of salvation is true?

We can know the message of salvation is true by examining Scripture, which reveals a consistent narrative of God's redemptive work. John the Baptist's proclamation, as noted in Matthew 3, underscores the essential nature of repentance leading to salvation. Furthermore, in John 1:29, John calls Jesus 'the Lamb of God, which taketh away the sin of the world,' reinforcing that Christ's work is not only foretold but realized in history. The truth of the Gospel is anchored in God’s fidelity to His promises and the fulfillment of prophecies through Christ's life, death, and resurrection, presenting a cohesive argument for the truth of salvation.