Agnus Dei is a Latin phrase that means “Lamb of God,” a title ascribed to Jesus. The reference goes back to Exodus 12 when the Israelites were slaves in Egypt. The Israelites were instructed to sacrifice an unblemished male lamb. Blood from the lamb was to be placed on their doorposts, and for those who complied, the tenth and final plague striking down all the firstborns would pass over their home and they would be spared. The lamb was also to be roasted and, along with unleavened bread, provided their final meal before leaving Egypt. As a reminder of this, the Israelites annually celebrated the Passover.
The prophecy in Isaiah 53 describes the Messiah as a sacrificial lamb who bears the sins of His people, connecting the Passover as a foreshadowing of the Savior to come. As Jesus began His ministry in John 1, John the Baptist publically identified Jesus as “the Lamb of God who takes away the sin of the world!” As Jesus makes final preparations for going to the cross, He celebrates the Passover with His disciples, saying, “This is My body,” and “This is My blood,” instituting the Lord’s Supper. After the resurrection of Jesus, Paul says in 1 Corinthians 5, “Christ our Passover has been sacrificed.” In Revelation 5, Jesus is depicted as a Lamb, of Whom is said, “You were slain, and by Your blood You ransomed for God saints from every tribe and language and people and nation.”
As we celebrate the Lord’s Supper, we are reminded that Jesus is our Passover Lamb who was sacrificed, shedding His blood on the cross for our forgiveness, and as we sing the Agnus Dei, we recognize the presence of the Lamb of God in this sacrament.