How do we know that Christ's sacrifice for sin is true?

The truth of Christ's sacrificial death is established in numerous passages throughout scripture, particularly in John 1:29, where John the Baptist identifies Jesus as the Lamb of God who takes away the sin of the world. Furthermore, Hebrews 9:22 states that without the shedding of blood, there is no forgiveness of sins, establishing the necessity of Christ's blood for our redemption. Through His sacrifice, we have eternal life as described in 1 John 5:11, which assures us that this life is in His Son.