When John says of Jesus 'Behold the Lamb of God who takes away the sins of the world', He is not quoting any Old Testament verse but rather is summarizing all the the Old Testament pointed to through the sacrificial system. The people's lambs could never remove sin; they only served God's purpose until His Lamb came to deal with sin once and for all.
Topics:
discipleship, faith, hope, Jesus Christ, prophecy, repentance, salvation, thankfulness; worship