Penal substitution, also called penal substitutionary atonement and especially in older writings forensic theory,[1][2] is a theory of the atonement within Protestant Christian theology, which declares that Christ, voluntarily submitting to God the Father's plan, was punished (penalized) in the place of (substitution) sinners, thus satisfying the demands of justice and propitiation, so God can justly forgive sins making us at one with God (atonement). It began with the German Reformation leader Martin Luther and continued to develop within the Calvinist tradition[1][2][3][4][5] as a specific understanding of substitutionary atonement. The penal model teaches that the substitutionary nature of Jesus' death is understood in the sense of a substitutionary fulfilment of legal demands for the offenses of sins.
^ abSmith, David (c. 1919). The atonement in the light of history and the modern spirit. Robarts – University of Toronto. London, Hodder and Stoughton. pp. 96–97. The Forensic Theory ... each successive period of history has produced its peculiar type of soteriological doctrine...the third period – the period ushered in by the Reformation.
^ abVincent Taylor, The Cross of Christ (London: Macmillan & Co, 1956), pp. 71–72: '...the four main types, which have persisted throughout the centuries. The oldest theory is the Ransom Theory...It held sway for a thousand years. ... The Forensic Theory is that of the Reformers and their successors.'
^J. I. Packer, What did the Cross Achieve? The Logic of Penal Substitution (Tyndale Biblical Theology Lecture, 1973): '... Luther, Calvin, Zwingli, Melanchthon and their reforming contemporaries were the pioneers in stating it [i.e. the penal substitutionary theory]...'
^H. N. Oxenham, The Catholic doctrine of the atonement (London: Longman, Green, Longman, Roberts, and Green, 1865), pp. 112–113,119: '...we may pause to sum up briefly the main points of teaching on Christ's work of redemption to be gathered from the patristic literature of the first three centuries as a whole. And first, as to what it does not contain. There is no trace, as we have seen, of the notions of vicarious satisfaction, in the sense of our sins being imputed to Christ and His obedience imputed to us, which some of the Reformers made the very essence of Christianity; or, again, of the kindred notion that God was angry with His Son for our sakes, and inflicted on Him the punishment due to us ; nor is Isaiah s prophecy interpreted in this sense, as afterwards by Luther; on the contrary, there is much which expressly negatives this line of thought. There is no mention of the justice of God, in the forensic sense of the word; the Incarnation is in variably exclusively ascribed to His love; the term satisfaction does not occur in this connection at all, and where Christ is said to suffer for us, huper (not anti) is the word always used. It is not the payment of a debt, as in St. Anselm's Cur Deus Homo, but the restoration of our fallen nature, that is prominent in the minds of these writers, as the main object of the Incarnation. They always speak, with Scripture, of our being reconciled to God, not of God being reconciled to us.' [pp. 112–113]; 'His [Jesus'] death was now [in the Reformation period], moreover, for the first time viewed as a vicarious punishment, inflicted by God on Him instead of on us.' [p. 119]