John 1:29 (ESV) … The next day he saw Jesus coming toward him, and said, “Behold, the Lamb of God, who takes away the sin of the world!”
Every morning and evening, a lamb was sacrificed in the temple for the sins of the people (Exodus 29:38–42). Isaiah 53:7 prophesied that the Messiah, God’s servant, would be led to the slaughter like a lamb. To pay the penalty for sin, a life had to be given - God chose to provide the sacrifice himself. When Jesus died as the perfect sacrifice, he removed the sin of the world and destroyed the power of sin itself. Thus God forgives our sin (1 Corinthians 5:7).
The “sin of the world” means the sin of each individual. Jesus paid the price of our sin by his death. We claim the forgiveness he provided by first taking ownership of our sin. If we insist we have no sin, then we gain no forgiveness. Repentance precedes forgiveness. If you don’t think you need to repent, check your life again. The Ten Commandments can help you evaluate how you’re doing by God’s standards.
Barton, B. B. (1993). John (p. 21). Wheaton, IL: Tyndale House.