For the life of a creature is in the blood, and I have appointed it to you to make atonement on the altar for your lives, since it is the lifeblood that makes atonement. Leviticus 17:11 (Christian Standard Bible, CSB)

The Bible says that atonement is provided through the blood. What exactly is atonement? According to the Student Bible Dictionary, to make atonement is defined:

“To cover or cancel one’s sins (Exodus 30:5-16). Making two into one (Romans 5:11). Atonement is motivated by the love of God, it occurs through the shedding of blood… Jesus made atonement so persons might become one with God. It’s meaning can be remembered by ‘At-one-ment with God.’”

In the Old Testament, atonement meant the covering of sin and it expired after a set period of time, meaning the sacrifice had to be offered many times. In the New Testament, the blood of Jesus resulted in atonement that canceled one’s sins and has no expiration date.

Romans 5:11 (KJV) says:

And not only so, but we also joy in God through our Lord Jesus Christ, by whom we have now received the atonement.

In some translations, atonement is translated reconciliation. Jesus’ blood reconciled us to God. Our sins have permanently been dealt with and man can now be one with God.

For God’s will was for us to be made holy by the sacrifice of the body of Jesus Christ, once for all time. Under the old covenant, the priest stands and ministers before the altar day after day, offering the same sacrifices again and again, which can never take away sins.  But our High Priest offered himself to God as a single sacrifice for sins, good for all time. Then he sat down in the place of honor at God’s right hand.  There he waits until his enemies are humbled and made a footstool under his feet.  For by that one offering he forever made perfect those who are being made holy. And the Holy Spirit also testifies that this is so. For he says, “This is the new covenant I will make with my people on that day, says the Lord: I will put my laws in their hearts, and I will write them on their minds.” Then he says, “I will never again remember their sins and lawless deeds.” And when sins have been forgiven, there is no need to offer any more sacrifices. Hebrews 10:10-18 (New Living Translation, NLT)