Sometime in the first half of the first century A.D., John the Baptist was out in the sticks of Israel yelling at people (I'm not the only one whose loud when they preach) and then holding some of them under water when he saw his cousin Jesus walking by and screamed:
"Look! There is the Lamb of God who takes away the sin of the world!" John 1:29b
John is most certainly referring to the sacrificial lamb offered during Passover. During the 10th day of the Hebrew month of Abib (roughly April), a Jewish family would buy a spotless lamb and take it home. For 4 days, this lamb would hang around their house. Maybe they would tie it to a post in their back yard. The kids would want to play with it and pet it and feed it. Then on the 14 day of Abib the family would take the lamb to the Temple, lay their hands on it, pray over it and then slit its throat over a basin.
Why? Because God is holy, we are sinful and the product of sin is death. More on this later. Preaching on it this weekend.