John 1:29
The next day John saw Jesus coming toward him, and said, “Behold! The Lamb of God who takes away the sin of the world!”

This declaration is found from no other Gospel account, but what a declaration it is.
It is the link that ties together the Law and the Prophets with the New Covenant.
The single word “Lamb” explains the purpose of God to such a degree.
The lamb always held a special place in the Law. This sacred sacrificial animal first appears in the days of Moses, as the Israelites were slaves of Egypt.
The blood of the Passover lamb (Exodus 12) protected those that followed God’s planned use for it.
Several millennia later, Jesus would die at Passover, around the time the Passover lamb was slain at the Temple.
Like the first Passover lamb, the blood of Jesus cleanses us from sin (1 John 1:7) and protects us from death (Rev 7:14-17).
There is no sacrifice, no good deed, no philosophy, and no other way to stand accepted before God but by the blood of Jesus Christ.
And when I see the blood, I will pass over you; Ex 12:13