The judicial was system set up by the LORD and was given to the Israelites through Moses. Exodus, Leviticus, Numbers and Deuteronomy are all dedicated to issues of the law, sin, punishment and atonement. Sacrifices and Offerings were required for the purification of GOD's people, the removal of sin and the access to worship. The high priest first had to go through the ritual of purification before he could even enter into GOD's presence to mediate on behalf of a worshiper. GOD's says, "I am the LORD your God; consecrate yourselves and be holy, because I am holy." Leviticus 11:44
There are burnt offerings, SIN offerings, GUILT offerings, cereal offerings, PEACE offerings and special offerings. An unblemished animal is usually required and it's blood is sprinkled around the alter or on the worshiper for atonement for their sins.
"The priest is to take some of the blood of the guilt offering and put it on the lobe of the right ear of the one to be cleansed, on the thumb of his right hand and on the big toe of his right foot." Leviticus 14:14
Why THE BLOOD?
"For the life of a creature is in the blood, and I have given it to you to make atonement for yourselves on the altar; it is the blood that makes atonement for one's life." Leviticus 17:11
Why THE BLOOD OF JESUS?
“Unlike the other high priests, he does not need to offer sacrifices day after day, first for his own sins, and then for the sins of the people. He sacrificed for their sins once for all when he offered himself.” Hebrews 7:27
"He did not enter by means of the blood of goats and calves; but he entered the Most Holy Place once for all by his own blood, having obtained eternal redemption. The blood of goats and bulls and the ashes of a heifer sprinkled on those who are ceremonially unclean sanctify them so that they are outwardly clean. How much more, then, will the blood of Christ, who through the eternal Spirit offered himself unblemished to God, cleanse our consciences from acts that lead to death, so that we may serve the living God!" Hebrews 9:12-16
"For you know that it was not with perishable things such as silver or gold that you were redeemed from the empty way of life handed down to you from your forefathers, but with the precious blood of Christ, a lamb without blemish or defect." 1 Peter 1:18-19
"In him we have redemption through his blood, the forgiveness of sins, in accordance with the riches of God's grace that he lavished on us with all wisdom and understanding." Ephesians 1:7-8
"Since we have now been justified by his blood, how much more shall we be saved from God's wrath through him! For if, when we were God's enemies, we were reconciled to him through the death of his Son, how much more, having been reconciled, shall we be saved through his life!" Romans 5:9-10
So, the BLOOD of Jesus Christ brings justification, redemption, atonement and access into GOD's presence-if we open our hearts and accept through faith, Jesus Christ as our LORD and SAVIOUR. That is why we say, "There is POWER IN THE BLOOD OF JESUS."