Definition of expiate from Merriam-Webster

transitive verb

1a: to make amends for; permission to expiate their offences by their assiduous labours— Francis Bacon

b: to extinguish the guilt incurred by

2 obsolete : to put an end to

Obsolete usages often have hidden meanings about the thoughts and usage of words. In this case the obsolete usage renders a much clearer picture of words utter by our Lord on the Cross.

John 19:30 English Standard Version (ESV) When Jesus had received the sour wine, he said, “It is finished,” and he bowed his head and gave up his spirit.

One of the important benefits of the expiatory sacrifice of Christ on the Cross was putting an end to the obedience to the law as a means of being seen as righteous in God’s sight. We no longer have to perfectly obey all the law in order to be right with God.

The Old Testament issue of atonement was defined as a covering, not a removal. Sin became a thing hidden from God’s sight. Propitiation is not a covering, it is a substitution, a removal and casting away of sin and the designed replacement with the righteousness of God Himself in the person of Jesus Christ.

This is written without scriptural context. Does the Holy Spirit confirm this to be true? Each of us that have the abiding Spirit are able to confirm truth by virtue of agreement in the Spirit. Spirit speaks to Spirit by confirming truth.

Romans 9:1 English Standard Version (ESV) I am speaking the truth in Christ—I am not lying; my conscience bears me witness in the Holy Spirit—

Disciples require definitions, scriptures, teaching and at some point develop discernment. The mature Christian who has rightly divided the Word of truth is able to distinguish between truth and failed doctrine.

Romans 3:19-26 English Standard Version (ESV)

¹⁹ Now we know that whatever the law says it speaks to those who are under the law, so that every mouth may be stopped, and the whole world may be held accountable to God. ²⁰ For by works of the law no human beingwill be justified in his sight, since through the law comes knowledge of sin.

The Righteousness of God Through Faith

²¹ But now the righteousness of God has been manifested apart from the law, although the Law and the Prophets bear witness to it— ²² the righteousness of God through faith in Jesus Christ for all who believe. For there is no distinction: ²³ for all have sinned and fall short of the glory of God, ²⁴ and are justified by his grace as a gift, through the redemption that is in Christ Jesus, ²⁵ whom God put forward as a propitiation by his blood, to be received by faith. This was to show God’s righteousness, because in his divine forbearance he had passed over former sins. ²⁶ It was to show his righteousness at the present time, so that he might be just and the justifier of the one who has faith in Jesus.

This is the essence of the New Covenant. Hidden within these verses is a critical point upon which all salvation hangs in the balance. In verse 20 it can be noted that we need to be justified in God’s sight. Justification is the key element of all salvation and the major difference between the Old Testament and the New Testament.

Strong’s Expository Encyclopedia defines justification in this way; “a sentence of acquittal,” by which God acquits men of their guilt, on the conditions

(1) of His grace in Christ, through His expiatory sacrifice,

(2) the acceptance of Christ by faith,

In Christ, God’s need for justice is satisfied. The word propitiation means acceptable substitute, His expiatory sacrifice.