Here is the reasoning behind the ESV choice for propitiation,
- Another example of an important correction to the RSV was the translation of the Greek word hilasterion and its cognates (Rom. 3:25, Heb. 2:17, 1 John 2:2 and 1 John 4:10) which the RSV translated "expiation." The ESV corrected this to "propitiation." Propitiation means to appease the wrath of someone by the substitution of an offering. Thus Jesus bore the wrath of God that was due mankind. The righteous anger that was due mankind was placed upon His Son. Christ's sacrifice had the effect of both bearing the sin of man (expiation) and the punishment due man for his wickedness (propitiation).
It is worth noting that the NIV and the NRSV both took the "middle ground" and translated hilasterion as "atonement." In so doing the translators decided not to take a stand on the issue since "atonement" captures both expiation and propitiation. Clearly, many modern translations have not translated hilasterion as propitiation for the simple reason that it does not fit their theology. That God's wrath needed to be appeased was contrary to their understanding of God. Both the "Message," and the CEV translations have removed the heart of the meaning of propitiation from their respective translations entirely. (See Romans 3:25)
- Christian language, with its peculiarities, has been much studied during the past twenty years, and two things about it have become clear, First, all its odd, ‘stretched’, contradictory and incoherent-sounding features derive directly from the unique Christian notion of the transcendent, tripersonal Creator-God. Christians regard God as free from the limits that bind creatures like ourselves, who bear God’s image while not existing on his level, and Christian language, following biblical precedent, shakes free from ordinary limits in a way that reflects this fact. So, for instance, faced with John’s declaration in 1 John 4:8-10, ‘God is love. . . . Herein is love, not that we loved God, but that he loved us, and sent his Son to be the propitiation for our sins,’ Calvin can write without hesitation: ‘The word propitiation (placatio; Greek, hilasmos) has great weight: for God, in a way that cannot be put into words (ineffabili quodam modo), at the very time when he loved us, was hostile (infensus) to us till he was reconciled in Christ.’7 Calvin’s phrase ‘in a way that cannot be put into words’ is his acknowledgement that the mystery of God is beyond our grasp. To Calvin, this duality of attitude, love and hostility, which in human psychological terms is inconceivable, is part of God’s moral glory; a sentiment which might make rationalistic theologians shake their heads, but at which John certainly would have nodded his.
I have just found this website which provides these early versions in modern spelling for comparison. It also provides the Tyndale OT books. Here is a verse, 1 John 4:10, which gives us some idea of the difficulties of translating ἱλασμὸν.
- 10 In this thing is charity, not as we had loved God, but for he first loved us, and sent his Son forgiveness for our sins [and sent his Son helping for our sins] . Wycliffe
10 Herein is love, not that we loved God, but that he loved us, and sent his son to make agreement [a satisfaction] for our sins. Tyndale/Coverdale
10 Herein is that love, not that we loved God, but that he loved us, and sent his Son to be a reconciliation for our sins. Geneva
10 In this is love, not that we loved God, but that he loved us, and sent his Son to be the propitiation for our sins. KJV (Websters)