From the 1823 Webster’s Dictionary,

“Atonement,

1. Agreement; concord; reconciliation, after enmity or controversy.            2. Expiation; satisfaction or reparation made by giving an equivalent for an injury, or by doing or suffering that which is received in satisfaction for an offense or injury; with for. “And Moses said to Aaron, go to the altar, and offer thy sin-offering, and thy burnt-offering, and make an atonement for thyself and for the people.” Leviticus 9:7.                  3. In theology, the expiation of sin made by the obedience and personal sufferings of Christ.”

ATO’NE, adverb [at and one.] At one; together.                  ATO’NE, verb intransitive [Supposed to be compounded of at and one. Latin ad and unus, unio.]

To stand as an equivalent; to make reparation, amends or satisfaction for an offense or a crime, by which reconciliation is procured between the offended and offending parties.

To atone for, to make compensation or amends.”

The question for now is, “What is the Atonement” as found in Scripture?  In the Word of God we find God’s Son as the Suffering Servant paying the penalty for the sins of humankind. On the Cross, we observe the effects of our sin falling upon Jesus Christ and we are reconciled to God by our expression of faith in Him. Jesus Christ was the only One capable of carrying out the Atonement for all mankind. We most often use the word ‘redemption,’ and therefore refer to the Lord Jesus as our Redeemer.

Historically speaking the word ‘atonement’ was not utilized as a theological term but only in expressions concerning “reconciliation,” and most often as a transaction between two entities. However, it took on a more exclusively among religious bodies for theological understanding.

The word is used only in the Old Testament and primarily in the first five books of the Pentateuch. Never do we find atonement being used in the New Testament. And this word is curiously absent although we use it often in Bible Studies discussing salvation.

As discussed,  in the OT ‘atonement’ speaks of a person being cleansed from sin or defilement in some way: 

“This is the law of the one who bears a child, for the male or the female child. If she cannot afford a sheep, then she must take two turtledoves or two young pigeons, one for a burnt offering and one for a sin offering, and the priest is to make atonement on her behalf, and she will be clean.’” Leviticus 7b-8 NASB.

 Some diseases were healed and we find, “The priest must then perform the sin offering and make atonement for the one being cleansed from his impurity. After that he is to slaughter the burnt offering, and the priest is to offer the burnt offering and the grain offering on the altar. So the priest is to make atonement for him and he will be clean.” Leviticus 14:19.

However, most commonly the word is employed for sacrifices for individual sinners. In Leviticus chapter 16 is found the commandment from God explaining the Day of Atonement for sins of the Nation of Israel being cleansed by animal sacrifice.

Paul writes that Christ died “for our sins” in 1 Corinthians and in Galatians. “Now I want to make clear for you, brothers and sisters, the gospel that I preached to you, that you received and on which you stand, and by which you are being saved, if you hold firmly to the message I preached to you—unless you believed in vain. For I passed on to you as of first importance what I also received—that Christ died for our sins according to the scriptures, and that he was buried, and that he was raised on the third day according to the scriptures.” 1 Corinthians 15:1-4 and “I have been crucified with Christ, and it is no longer I who live, but Christ lives in me. So the life I now live in the body, I live because of the faithfulness of the Son of God, who loved me and gave himself for me.” Galatians 2:20-21 NET2.  Before the death of Christ, our sins separated us from God. After His death our sins were transferred to Christ, and “He Himself bore our sins in His body on the cross, so that we might die to sin and live to righteousness; for by His wounds you were healed. For you were continually straying like sheep, but now you have returned to the Shepherd and Guardian of your souls.” 1 Peter 2:24-25 NASB.

Because of the sacrifice of Christ, Believers have been saved, justified, forgiven, and adopted into the Body of Christ, the Church. No one can describe what we have in Christ. Yes, ‘atonement’ is not used in the New Testament, and in the Old Testament is enough explanation for the sacrifice of Christ for lost sinners.

“But God, who is rich in mercy, because of His great love that He had for us, made us alive with the Messiah even though we were dead in trespasses. You are saved by grace! Together with Christ Jesus He also raised us up and seated us in the heavens, so that in the coming ages He might display the immeasurable riches of His grace through His kindness to us in Christ Jesus. For you are saved by grace through faith, and this is not from yourselves; it is God’s gift — not from works, so that no one can boast. For we are His creation, created in Christ Jesus for good works, which God prepared ahead of time so that we should walk in them.” Ephesians 2:4-10 HCSB.

Jesus is Lord.