1 Pt 1:19, Jn 19:36, 2 Cor 5:21, Jn 1:29, Isa 53:5-6
In the Old Testament, when offering sacrifices to God, an ox, sheep, or goat without blemish had to be offered. (Lev 22:18-20)
Lev 22:18 peak unto Aaron, and to his sons, and unto all the children of Israel, and say unto them, Whatsoever he be of the house of Israel, or of the strangers in Israel, that will offer his oblation for all his vows, and for all his freewill offerings, which they will offer unto the Lord for a burnt offering; 19 Ye shall offer at your own will a male without blemish, of the beeves, of the sheep, or of the goats. 20 But whatsoever hath a blemish, that shall ye not offer: for it shall not be acceptable for you.
In the Old Testament, it was prophesied that Christ would bear our sins, suffer and die in order to save us. (Isa 53:5-6)
Isa 53:5 But he was wounded for our transgressions, he was bruised for our iniquities: the chastisement of our peace was upon him; and with his stripes we are healed. 6 All we like sheep have gone astray; we have turned every one to his own way; and the Lord hath laid on him the iniquity of us all.
Jesus is the Lamb of God, without blemish and without spot. Jesus, who knew no sin, took our sins and died on the cross in order to save us. (John 1:29, 1 Peter 1:19, 2 Corinthians 5:21)
John 1:29 The next day John seeth Jesus coming unto him, and saith, Behold the Lamb of God, which taketh away the sin of the world.
1 Peter 1:19 But with the precious blood of Christ, as of a lamb without blemish and without spot:
2 Corinthians 5:21 For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him.