The Greek word ιλαστηριον/hilasterion -which itself can be translated as either “propitiation” or “expiation”- is found in the NT but a few times (the most important instances for the doctrine of atonement are three: Rom 3:25; 1 Jn 2:2; 4:10); major scholarship as well as historic theological trajectories have long wrestled with the issue of which translation best conveys the meaning of the few NT passages which employ it, and the answer to this basic query does have broad and important theological implications.
The most important NT passages are:
(1) Rom 3:25: “…whom God displayed publicly as a/an _____________ in His blood through faith. This was to demonstrate His righteousness, because in the forbearance of God He passed over the sins previously committed”
(2) 1 John 2:2: “…and He Himself is the ______________ for our sins; and not for ours only, but also for those of the whole world.
(3) 1 Jn 4:10: “This is love: not that we loved God, but that he loved us and sent his Son as an ______________ for our sins.
So what’s the difference? A short passage from “Reconciliation,” in Colin Brown, ed., New International Dictionary of New Testament Theology, Vol. III, p. 151 (hereafter referred to as DNTT) summarizes:
“In discussing reconciliation and atonement it has become customary to draw a distinction between propitiation and expiation. In propitiation the action is directed towards God, or some other offended person. The underlying purpose is to change God’s attitude from one of wrath to one of good will and favor. In the case of expiation, on the other hand,the action is directed towards that which has caused the breakdown in the relationship… In short, propitiation is directed towards the offended person, whereas expiation is concerned with nullifying the offensive act” (DNTT, Vol. III, p. 151).
“Propitiate,” then, indicates God is changed; “expiate” indicates the repentant sinner is changed. But this raises another question to which our first one is related: does God change? (our answer will be of the traditional classical theist “God does not change” variety rather than the more recent open theist “God does grow and change” variety; we will then return to the question of whether propitiation or expiation best approximates what Gk. ιλαστηριον conveys in the NT).
To illustrate why some raise a question as to whether God changes or not in the first place we will consider very briefly how there are some passages in the Bible that on the face of it “seem” to indicate that God changes in some sense (unspecified), and others which say that He does not (we affirm that descriptions of God’s “changes of mind” are more phenomenological (how things are encountered in relational experience by changing observers) than ontological (what God’s mind and being actually “are” (cf. Is 55:8-9).
Mal 3:6: “I the LORD do not change. So you, O descendants of Jacob, are not destroyed.”
Jas 1:17: “Every good and perfect gift is from above, coming down from the Father of the heavenly lights, who does not change like shifting shadows.”
Num 23:19: “God is not a man, that he should lie, nor a son of man, that he should change his mind. Does he speak and then not act? Does he promise and not fulfill?”
Ex 32:14 “So the LORD changed His mind about the harm which He said He would do to His people.”
Jer 26:19 “Did Hezekiah king of Judah and all Judah put him to death? Did he not fear the LORD and entreat the favor of the LORD, and the LORD changed His mind about the misfortune which He had pronounced against them? But we are committing a great evil against ourselves.”
Amos 7:1-3 “Thus the Lord God showed me, and behold, He was forming a locust-swarm when the spring crop began to sprout. And behold, the spring crop was after the king’s mowing. And it came about, when it had finished eating the vegetation of the land, that I said, “Lord God, please pardon! How can Jacob stand, For he is small? The LORD changed His mind about this. “It shall not be,” said the LORD” (cf. also vs 6).
Ex 4:24-26 “Now it came about at the lodging place on the way that the LORD met him and sought to put him to death. Then Zipporah took a flint and cut off her son’s foreskin and threw it at Moses’ feet, and she said, “You are indeed a bridegroom of blood to me.” So He let him alone. At that time she said, “You are a bridegroom of blood “– because of the circumcision.”
According to church historian Jaroslav Pelikan major historic Christian heresies usually arise not so much as instances of obvious logical error or rank ignorance of scripture as by emphasis of one pole of a dialectical or fuller truth. Some might argue the diverse passages which describe both apparent instances and actual impossibility of divine change are simply careless contradictions. At the very least this is less likely if their respective authors knew well what had been written elsewhere by other biblical writers -and we must in this connection recall both emphases are not once but multiply attested in the biblical corpus. Still, even if we then suppose a fuller truth was and is afoot in these passages (as the current writer suspects), we still are faced with yet another example of the often delicate balance between semantic and conceptual ambiguities (of which language as a whole is rife) and the goals and methods of systematic theology to the extent that it becomes a more “rationalized” enterprise (propitiation/expiation is itself an illustration of scholarly and systematic polarity arising from linguistic/conceptual ambiguity). Karl Barth’s remark that “systematization is the enemy of true theology” is to this extent an apt reminder of the limitations of any theological methodology that is to any degree “purely human.” If such a thing as true theology genuinely exists (as the present writer does believe) it perhaps belongs more to the province of the Spirit who both reveals and illumines things revealed than to the machinations and extrapolations of the rational system builder who makes flesh, intellect, or academic theories of hermeneutics, exegesis, etc. his or her strength (not to say these must be intrinsically adversarial or without divinely ordered or mediated congruence; here as elsewhere there is an element of the mysterious where the matter at hand is incarnational):
“Open thou mine eyes, that I may behold wondrous things out of thy law” -Psalm 119:18
“He that loveth not knoweth not…” -1 Jn 4:8
But let us return now to our topic of change and hilasterion/ιλαστηριον…
Note that the blessing of obedience/prayer/intercession and cursing of disobedience according to the covenant do not change in any of the above examples. In this sense one can certainly maintain God did not change his mind in any of the above instances, though he is admittedly said to have in anthropomorphic/phenomenological terms. He did what he stated he would do from the beginning; what that is in particular varies in accordance with what men do (as we will see with reference to Deut 28 shortly).
One author -I have long since forgetten who- used a wind analogy to illustrate this more plainly. If I am walking against a strong wind, and turn around, I may say “the wind was against me but is now with me.” But the wind didn’t really change; it was I who changed direction in relation to the wind.
Deut 28:13-20 13 “And the LORD shall make you the head and not the tail, and you only shall be above, and you shall not be underneath, if you will listen to the commandments of the LORD your God, which I charge you today, to observe them carefully, and do not turn aside from any of the words which I command you today, to the right or to the left, to go after other gods to serve them. But it shall come about, if you will not obey the LORD your God, to observe to do all His commandments and His statutes with which I charge you today, that all these curses shall come upon you and overtake you. Cursed shall you be in the city, and cursed shall you be in the country. Cursed shall be your basket and your kneading bowl. Cursed shall be the offspring of your body and the produce of your ground, the increase of your herd and the young of your flock. Cursed shall you be when you come in, and cursed shall you be when you go out. The LORD will send upon you curses, confusion, and rebuke, in all you undertake to do, until you are destroyed and until you perish quickly, on account of the evil of your deeds, because you have forsaken Me.”
Having touched upon the question of change, we can now return to our original question about the meaning of ιλαστηριον in the NT, whether it is more closely approximated by propitiation or expiation.
Representing the perspective of patristic theology of the first Christian millennium, Orthodox theologian and Bishop Kallistos Ware has insisted that Christ did not become incarnate to heal God the Father: He became incarnate to heal us. According to the Orthodox the cross, resurrection, and ascension of Christ represent the “mercy seat” (Gk hilasterion/Heb. kippur) upon which our sins are “wiped away”/”expiated” by God, restoring us to His covenant love and transforming repentant sinners into His own divine likeness and nature (2 Cor 3:18; 1 Pet 1:4 etc.); it is we who change rather than God; God never does (Mal 3:6; Jas 1:17). Orthodoxy emphasizes the divine attribute of constancy.
If we concede the classical theist position that God Himself remains ever constant, and that any change effected is in man rather than a change within God, we must also concede that divine propitiation -a change in attitude from one of wrath to one of good will and favor- cannot describe an ontological change in the being of God. God cannot have been propitiated ontologically in the sense of having “a change of attitude” unless God Himself changes ontologically.
There is one final point to be made from the perspective of exegesis. In the case of expiation, we will recall, “the action is directed towards that which has caused the breakdown in the relationship… In short, propitiation is directed towards the offended person, whereas expiation is concerned with nullifying the offensive act” (DNTT III, 173). So to what do the three major passages refer? Are they referring to God (as in God’s wrath being propitiated) or to the sins being wiped away? (expiation) As it happens, in none of the passages in question is ιλαστηριον used directly of God at all, but it is used directly of our sins:
1 John 2:2: “…and He Himself is the ______________ for our sins; and not for ours only, but also for those of the whole world.
Not the ιλαστηριον for the Father, but for our sins, and not ours only, but also for those of the whole world.
1 Jn 4:10: “This is love: not that we loved God, but that he loved us and sent his Son as an ______________ for our sins.
Not a ιλαστηριον for the Father, but “for our sins.”
Rom 3:25: “…whom God displayed publicly as a/an _____________ in His blood through faith. This was to demonstrate His righteousness, because in the forbearance of God He passed over the sins previously committed”
Not to demonstrate Christ changed the Father’s attitude, but that God passed over sins previously committed.
 We should note in passing that open view and process theists argue against this; full discussion of these alternatives is beyond the scope of the current article.
 As St. Ephrem of Syria held many centuries before Barth, and as is also intrinsic to the theological category of phronema/φρόνημα.
 In referring to patristic theology of the first Christian millennium we should emphasize this is not an exclusively patristic or Orthodox view; as was mentioned earlier leading academic scholars, and major Protestant scholars, have held ιλαστηριον is best understood as expiation -change of man, wiping away his sin- rather than propitiation -change of God, changing His disposition from temper to affection. To hold this position does not entail that the wrath of God is a mere anthropopathism, but God is constant and changeless in His opposition to sin and his receptivity to those who seek His mercy. It is we who must be transfigured by the grace and mercy of God. God and Christ are the same yesterday, today, and forever. The Latin Catholic tradition, by contrast, has insisted (though only since the middle ages) upon the sense of propitiation, as also has classical Calvinist interpretation. Historically the emphasis upon a change in God’s attitude rather than man’s condition arose in the middle ages with Anselm, according to whom man had broken honor with his liege Lord; because his honor was slighted “satisfaction” had to be made (civil law model rather than criminal law; pivotal for subsequent developments of Latin Catholic theories of merit, superabundant merit, storehouses of merit, indulgences, and Protestant redirection of soteriological merit to the infinite merit of Christ (Protestant soteriologies are actually soteriologies of merit -the focus of merit/satisfaction is simply shifted from man to Christ. Eastern Orthodox Christian theology bypassed this particular Western controversy entirely as they never adopted a soteriology of merit/satisfaction (ala Anselm): the atonement is purely grace/gifting rather than merit/earning even on the divine side).
 On the basics of the conceptual origin and development of Latin Catholic and Protestant theologies of merit -from condign merit to congruent merit in the Christian West- see further here and here)