"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."
Extract from "The Logic of Penal Substitution" by J I Packer