Why did John the Baptist call Jesus the lamb?

In the Old Testament book of Exodus, the Hebrews (a Word which means 'wanderers') were told to sacrifice a lamb the night before their escape from Egypt. Here are comparisons between the lamb and Christ: 1) The Hebrews were to eat the lamb as nourishment for the journey: Christ, in the Eucharist gives Christians His Body as nourishment for our journey through life. 2) The lamb was to be without blemish: Christ is without blemish (i.e. sin) 3) The blood of the lamb was to be smeared on the wood of the lintel so that the Angel of Death would pass over without taking the life of the firstborn: Christ's Blood was smeared (shed) on the wood of the Cross and our lives have been spared from eternal death. 4) Thus, the sacrifice of the lamb indirectly saved the people from slavery and enabled them to be led to the Promised Land of Israel: the sacrifice of Christ directly freed us from the slavery of sin and enables us to be led to the Promised Land of Heaven.