Jesus is frequently referred to as the lamb of God throughout the New Testament.  Here are four examples.

• John the Baptist used this title at Jesus’ baptism: The next day he saw Jesus coming toward him, and said, “Behold,  the Lamb of God, who  takes away the sin  of the world!  (John 1:29)
• Paul described Jesus in this way: Your boasting is not good. Do you not know that a little leaven leavens the whole lump? Cleanse out the old leaven that you may be a new lump, as you really are unleavened. For Christ, our Passover lamb, has been sacrificed. Let us therefore celebrate the festival, not with the old leaven, the leaven of malice and evil, but with the unleavened bread of sincerity and truth. (1 Corinthians 5:6-8)
• As well as Peter: And if you call on him as Father who judges impartially according to each one’s deeds, conduct yourselves with fear throughout the time of your exile, knowing that you were ransomed from the futile ways inherited from your forefathers, not with perishable things such as silver or gold, but with the precious blood of Christ, like that of a lamb without blemish or spot. (1 Peter 1:17-19)
• The most concentrated reference to Jesus as the Lamb are in the book of Revelation, written by John.  Here’s one example: And between the throne and the four living creatures and among the elders I saw  a Lamb standing, as though it had been slain, with seven horns and with  seven eyes, which are  the seven spirits of God sent out into all the earth.  (Revelation 5:6)

Why is Jesus called this by Paul, Peter and John?  It is in reference to the Passover where a lamb without blemish was sacrified and his blood sprinkled on the door post of the Israelite houses.  The blood protected people from the angel of death that killed the first born in the Egyptian families.  Read the complete story in Exodus 12 and 13.  Jesus fulfilled this Old Testament symbol by shedding His blood for us.  His blood protects us from God’s judgment of our sin if we repent of our sin and trust Jesus to save us rather than our own works (Ephesians 2:8-9).  Learn more about the Gospel and Who Jesus Is.