This idea of the Lamb of God is a strand that runs throughout the history of redemption. It can be traced all the way back to Genesis 22, when God called Abraham to go to Mount Moriah and offer his son Isaac as a sacrifice. Abraham, in obedience to God, was prepared to do just that, but at the last possible moment, after Abraham had tied Isaac to the altar and was preparing to plunge the knife into his heart, God stopped him, saying, "Do not lay your hand on the lad, or do anything to him; for now I know that you fear God, since you have not withheld your son, your only son, from Me" (v. 12). Then there was a ruckus behind Abraham, and he turned to see a ram that was caught in the thicket by its horns. God provided a lamb as a sacrificial substitute for Abraham's son. Of course, it is never stated in Genesis 22 that the ram Abraham caught and offered in the place of Isaac was an expiatory sacrifice. Nevertheless, it was a substitutionary sacrifice, and that is the idea that underlies the atonement of Christ. Jesus acts as our substitute, and God pours out His wrath on account of our sin onto Him instead of us. God, then, provides a Lamb of His own and accepts the life of that substitute.
God pours out His wrath on account of our sin onto Jesus instead of us.
Likewise, the Lamb of God is certainly prefigured in the Passover. When God prepared to bring His final plague on the Egyptians, the death of every firstborn male of the Egyptians, including the crown prince of the Pharaoh, He instructed His people Israel to slay lambs without blemish and to spread the blood on their doorposts. God promised to pass over all the houses where He saw the blood of the lambs on the doorposts (Ex. 12:3–13). Just as the blood of those lambs caused the people of Israel to be spared from God's wrath, the Lamb of God redeemed His people from the penalty that was due for their sin.
Given this imagery in Genesis 22, Exodus 12, and other passages throughout the Old Testament, it's foolish to say that the title "Lamb of God" is an invention of the apostle John. The words of John the Baptist were informed by his knowledge of the Old Testament, the sacred Scriptures of the Jews at the time of Christ.
Despite the abundant use of significant titles for Jesus in the first chapter of John—"Lamb of God," "Son of God," "Messiah," "Son of Man," and so forth—I don't believe that John the Baptist, Andrew, Nathanael, or any of the disciples had a comprehensive understanding of the meaning of these titles. John the Baptist, who here said, "Behold! The Lamb of God who takes away the sin of the world!" later was thrown into prison and sent messengers to Jesus, asking, "Are You the Coming One, or do we look for another?" (Luke 7:20). This question indicates that John had not fully understood the identity of Jesus, despite his dramatic testimony to Jesus' identity. The problem was that he had his own expectations. He expected that the Lamb of God would come and drive the Romans out, just as everybody else did. When he saw Jesus merely going about preaching, he became confused.
The Lamb of God redeemed His people from the penalty that was due for their sin.
Jesus told John's messengers, "Go and tell John the things you have seen and heard: that the blind see, the lame walk, the lepers are cleansed, the deaf hear, the dead are raised, the poor have the gospel preached to them" (Luke 7:22). Jesus pointed to His miracles to confirm His identity for the doubting John. He also referenced the messianic prophecy in Isaiah 61:1–2a, which says:
"The Spirit of the Lord GOD is upon Me,
Because the LORD has anointed Me
To preach good tidings to the poor;
He has sent me to heal the brokenhearted,
To proclaim liberty to the captives,
And the opening of the prison to those who are bound;
To proclaim the acceptable year of the LORD."
It was as if Jesus was saying: "John, if you had really studied your Bible, you wouldn't be asking whether I am the One who was to come. You don't have to look for another one. You had it right the first time. I am the Lamb of God."
Peter was likewise confused, even when he gave his great confession at Caesarea Philippi. In answer to Jesus' question as to whom the disciples thought Him to be, Peter said, "You are the Christ, the Son of the living God" (Matt. 16:16). Jesus affirmed that confession to be accurate and declared Peter "blessed" for understanding who He was. But immediately afterward, when Jesus told His disciples that He was bound to Jerusalem to suffer and die, Peter rebuked Him and said, "This shall not happen to You!" (16:22b). One minute Peter affirmed that Jesus was the Messiah, but the next minute he revealed that he didn't really understand all that it meant for Jesus to be the Messiah.
We, of course, are prone to the same confusion. Only when we look at the whole picture, taking into account the cross, the resurrection, the ascension, and the outpouring of the Spirit at the Day of Pentecost, do we begin to see the depths and the riches of all that God was communicating through the announcement of His messenger, who said, "Behold! The Lamb of God who takes away the sin of the world!"
This post is an excerpt from R.C. Sproul's commentary on John__.