Jesus is the Lamb of God who takes away the sin of the world
Matthew 26:26–29 (ASV)
26And as they were eating, Jesus took bread, and blessed, and brake it; and he gave to the disciples, and said, Take, eat; this is my body. 27And he took a cup, and gave thanks, and gave to them, saying, Drink ye all of it; 28for this is my blood of the covenant, which is poured out for many unto remission of sins. 29But I say unto you, I shall not drink henceforth of this fruit of the vine, until that day when I drink it new with you in my Father’s kingdom.
John 1:29 (ASV)
29On the morrow he seeth Jesus coming unto him, and saith, Behold, the Lamb of God, that taketh away the sin of the world!
An decorated military man who murdered his own friend was being haunted by his incredibly evil deed. Nothing he did brought him any reprieve, until at last, he met Titus Coan who pointed him to "the Lamb of God who taketh away the sins of the world."