Propitiation occurs four times in the bible: Rm 3:25; Hb 2:17; 1 Jn 2:2 and 1 Jn 4:10. Romans is an undisputed letter by the apostle Paul but the author of Hebrews is unknown (Apollos?) and some critical scholars claim that 1 John was not written by a different John than the disciple John.
So if Romans 3:25 explains Christs death as a propitiation then the verse vindicates Hebrews and 1 John.
I have learned that many books have been written about Romans 3:25 in attempts to prove that Paul did not mean to use the word "propitiation" but rather "expiation."
Propitiation means that all of the redemption is done by Christ, but expiation can mean that Christ provided a way for man to do works to obtain redemption. "Propitiation" is the correct word, and therefore means that salvation is totally an act of Christ that he bestows on individuals, opposed to the incorrect understanding of "expiation" that implies that Jesus has provided a work that we may choose to reconcile ourselves to god to obtain salvation.
Some people consider "faith" as a work of fiction unless Romans 3:25 is understood as "expiation," but the New Testament writers considered "faith" in a different dichotomy than "works" (Eph 2:8-10).
I understand faith as an expression of the change God has made in the individual, and not an action that leads to salvation. I see good works also as a result of imputed righteousness that the Christian is enabled to do good works. The good works are also evidence of a change done to the character of the believer.
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.
Propitiation versus Expiation
The Greek word hilasterion is the Greek rendering of the Hebrew kapporeth which refers to the Mercy Seat of the Arc. Hilasterion can be translated as either propitiation or expiation which then imply different functions of the Mercy Seat.
Propitiation literally means to make favorable and specifically includes the idea of dealing with God’s wrath against sinners. Expiation literally means to make pious and implies either the removal or cleansing of sin.
The idea of propitiation includes that of expiation as its means; but the word "expiation" has no reference to quenching God’s righteous anger.
The difference is that the object of expiation is sin, not God. One propitiates a person, and one expiates a problem. Christ's death was therefore both an expiation and a propitiation. By expiating (removing the problem of) sin God was made propitious (favorable) to us.
The case for translating hilasterion as "expiation" was put forward by C. H. Dodd in 1935 and at first gained wide support. As a result hilasterion has been translated as ‘expiation’ in the RSV and other modern versions.
But a generation of debate has shown that the linguistic evidence seems to favor “propitiation” (cf. Matthew Black, Romans, New Century Bible, Oliphants, London,1973, p. 68, and also David Hill, Greek Words and Hebrew Meanings, Cambridge University Press, 1967, pp. 23-48).
Theologians stress the idea of propitiation because it specifically addresses the aspect of the atonement dealing with God's wrath.
Critics state that seeing the atonement as appeasing God is a pagan idea that makes God seem tyrannical. In response to this theologians have traditionally stressed that propitiation should not be understood as appeasing or mollifying God in the sense of a bribe or of it making an angry God love us because it is God who - both in the Old and New Testaments - provides the propitiation.
"I have given it to you upon the altar to make atonement for your souls" (Lev 17:11). God out of his love and justice renders Himself favorable by his own action.
On this point proponents of penal substitution are virtually unanimous.
John Stott writes that propitiation "does not make God gracious...God does not love us because Christ died for us, Christ died for us because God loves us" (The Cross of Christ p.174)
Calvin writes “Our being reconciled by the death of Christ must not be understood as if the Son reconciled us, in order that the Father, then hating, might begin to love us”. (Institutes II 16:4)
Sources available by contacting me for further information.