"The next day John seeth Jesus coming unto him, and saith, Behold the Lamb of God, which taketh away the sin of the world" (John 1:29).
Since the first entrance of sin into the world, the shedding of the blood of a spotless lamb has been required by God as a substitute for the life of guilty but repentant sinners.
When God delivered Israel from Egypt, a lamb was offered, for each family, and the annual Passover supper was established. "They shall take to them every man a lamb, according to the house of their fathers, a lamb for an house" (Exodus 12:3). Then, for the whole nation, offered once a year, was a "kid of the goats" on the great Day of Atonement. "Then shall |the high priest| kill the goat of the sin offering, that is for the people. . . . And he shall make an atonement for the holy place, because of the uncleanness of the children of Israel, and because of their transgressions in all their sins" (Leviticus 16:15-16). But this was only symbolic, "for it is not possible that the blood of bulls and of goats should take away sins" (Hebrews 10:4).
An animal, whether slain for an individual, a family, or a nation, could at best only testify to faith in God's promises, and God, in His grace, could accept the shed blood as a temporary atonement (or "covering") for their sins. But there was still needed a real sacrifice that really could take away the sins of all believers everywhere--a perfect sacrifice that would do away with the need for any future sacrifices.
Then, finally, Christ came! As the true Lamb of God, He "offered one sacrifice for sins for ever" (Hebrews 10:12). He has, as far as our offended Creator is concerned, finally taken away the sin of the world. But He is not only the slain Lamb; one day, though all the anti-God leaders of the world system rise against Him, "the Lamb shall overcome them: for He is Lord of lords, and King of kings" (Revelation 17:14). HMM