Leviticus 17:11 ESV
For the life of the flesh is in the blood, and I have given it for you on the altar to make atonement for your souls, for it is the blood that makes atonement by the life.
If you've ever attempted to read through the Bible, you probably had the same reaction many Christians do when they reach the book of Leviticus: What are all these animal sacrifices about? This ancient sacrificial system of worship seems so foreign to us. Can you imagine having to bring a lamb for slaughter every time you want to confess your sin?
We tend to look back on all those bloody sacrifices and think, I’m sure glad that doesn't involve me! But if we pass too quickly over them, we’ll miss seeing what our salvation cost the Savior. You see, He was our blood sacrifice. Redemption wouldn't have worked if He’d simply died for us in His sleep, because “without shedding of blood there is no forgiveness” (Heb. 9:22).
The Israelites had the continual reminder of the cost of sin. But today, having never experienced the slaughter of thousands of animals, we often take our salvation lightly, not realizing what it required. The flogging and crucifixion of Christ was a bloody, messy scene. The horror of it should move us to tears of sorrow and gratitude for what He did to buy our salvation. Without the shedding of His blood, we’d be bound for hell and eternal separation from God.
Now, instead of dragging a lamb behind us to the altar, we rely upon the Lamb of God, who offered Himself as the sacrifice for our transgressions. His blood washed away our sin so we can one day stand in heaven, singing praise to the Lamb who purchased us with His blood (Rev. 5:9-10). How wonderful is our redemption, and how good is our God!
Reprinted from: http://www.intouch.org/read/magazine/daily-devotions/the-necessity-of-a-blood-sacrifice