Nobody can see the Lamb until God shows them their need for a sacrifice for their sins. This is done by miraculous work of the Holy Ghost in each individual who then comes to trust in Christ. Scripture many times describes the Lord Jesus as God's Lamb for us! He is our sacrifice to take away our sin, He is our salvation! In Abraham's case, God promised to provide a lamb Himself for a sacrifice, but it was not limited to that one time to save Isaac. Rather, Abraham came to understand God meant He would provide THE Lamb, the Messiah, one day for our sacrifice for our sin! The Passover Lamb is another old testament illustration of God's lamb. It was the blood of that lamb displayed on the doorposts of the house, that protected the people inside from the judgment and wrath of God passing through the land that very night. Paul makes it clear, that this Passover lamb pointed to our Lord Jesus. "Christ our Passover Lamb is sacrificed for us!" he declared. Paul also tied that Passover lamb and celebration to the Lord's Table. The Lord Jesus Himself repurposed the old Passover celebration as a remembrance of His becoming our Passover lamb. Jesus has thereby promised that when the wrath falls, God will pass over all His people who are under Christ's blood. Most prominent is the prophecy of Isaiah, how Messiah would be crushed and smitten by God for our own sins, laid upon Christ by God Himself. He would be "brought as a lamb to the slaughter." John the Baptist announced that Jesus was that long-promised Lamb of God, that takes away our sin. The Apostle John often equated Christ with God's Lamb. Worthy is the Lamb that was slain, Who has redeemed us to God by His blood!