Hebrews 9: 22
...All things are cleansed with blood, and without shedding of blood there is no forgiveness.
This verse is key to salvation. From the very beginning God taught that something or someone needed to die to cleanse from sin, killing the animals to provide Adam's and Eve's clothing.
Then when Cain and Abel offered their sacrifices, Abel brought a firstling lamb (a blood sacrifice), while Cain offered some of his vegetables (the work of his hands). Abel knew he deserved death, but Cain thought he could work his own way to God, and God did not accept his offering.
Then God gave the Law to codify this concept of a blood sacrifice.
This was God's plan from before the beginning, to send the Second Person of the Godhead to be the Sacrifice to redeem this race of Man. He was the Lord God Who always dealt with Mankind, then He broke into our World by being born as a Man, so He could die for us as the Lamb of God, the Perfect Sacrifice, that would not just cover, but actually wash away every stain of sin, making us pure enough to withstand the very presence of our very God, without burning up.
Our God is more than we can stand. His being is so intense, a human person would be destroyed in His full presence. "There shall no man see Me, and live" (Genesis 33:20).
When Moses was on the mountain, requesting to see Him, but only seeing His backside, he came back down that mountain with his face glowing. He didn't feel any different, he didn't even know he glowed, until they made him wear a veil.
When Jesus came the first time, it was to fulfill all the Law, and to be the Final, Perfect Sacrifice for sin. When He died on the Cross, He fulfilled all the sacrificial laws, beginning with the first one, in Leviticus 1.
This is the first sacrifice every person was required to offer, the personal sacrifice. The individual would bring his own animal to the priest, put his hand on its head (identifying with it), and it would then be slaughtered, offered on the altar, and its blood would be splashed on the sides of the altar. Jesus fulfilled this, His Precious Blood splashed on the sides of His altar, the Cross. He died individually for each one of us, for salvation. We all deserve death, and He took our place, one by one, to pay for our sins.
He also fulfilled the corporate sacrifice, for the Nation, when He bought the whole World; He is now our Owner by Creation and by purchase, our rightful Judge.
Jesus fulfilled over 400 Old Testament prophesies about the Messiah. He will fulfill the rest of them when He returns again, to set up His Kingdom on this Earth, and rule justly for 1000 years.
Even so, come, Lord Jesus!
