When Adam and Eve sinned, God shed innocent blood in order to make them clothes from animal skins (Genesis 3:21). This is a picture of the covering of righteousness that we receive when the Lord Jesus Christ died for us.
In Genesis 4 we read that Adam and Eve had two sons, Cain and Abel. They instinctively wanted to worship God. Cain sacrificed the fruit of the ground. Abel had already learned that God demanded blood, so he brought a lamb. God accepted the blood of Abel's lamb, but He did not accept Cain's offering. Why? Because "without the shedding of blood, there is no remission of sin" (Hebrews 9:22).
And God told Abraham to sacrifice his long-awaited son Isaac (Genesis 22). Just before Abraham plunged the dagger into the quivering heart of his son, an angel stopped him. Abraham saw a ram caught in a thicket. Isaac was set free, but an innocent animal's blood was shed instead.
Then, God wanted to deliver His people from bondage in the land of Egypt. On the night of the Passover, God instructed each house to slay a lamb and put the blood on their door. God said in Exodus 12:13, "When I see the blood, I will pass over you."
And in the tabernacle and later in the temple, thousands upon thousands of sheep, oxen, and turtle doves were killed and their blood spilt as sacrifices for sin.
And finally, the Lord Jesus Christ died upon the cross. His death was the fulfillment of all the prophecy and promises. Revelation 13:8 proclaims that He was slain before the foundation of the world. He came to die; He planned to die; He lived to die; and He was born to die.
Taken from "The Scarlet Thread through the Bible" by Love Worth Finding Ministries (used by permission).