The One Christ: St. Augustine's Theology of Deification
112 The Son's Descent teous and a son of God."70 This internal transformation is likewise stressed by the University of Navarre's López de Meneses who likewise judges Augustinian adoption to be one of actual transformation and not merely a nominal change. He writes that justification is "perfectly equivalent" [perfectamente equivalente] to deification for Augustine because it entails a change in the human person's very being [un cambio en el ser del hombre], making those called into adopted children and godsthrough-grace [dioses por gracia].71 To be adopted is thus to be brought into God's own life, to enjoy a new relationship as a co-heir alongside the Son, and to become one now enabled to join Christ in calling God "Father."
This new way of life for the creature, Augustine knew, was a magna beneuolentia, a magna misericordia: "He was born the only one and he did not want to remain the only one."72 The Father is revealed as willing to share his perfect and eternal love for the Son with humanity. The Son's uniqueness [unicus] does not demand his solitude [unus]. Rather, the Father's paternity is now manifested in one of two ways: eternally and naturally by the Son and by means of divine grace and adoption for created persons. As we have just seen, the Father's willingness to be "Father" to many is considered by Augustine to be "a great mercy." Let us now see how this new life with the Father through Christ is also considered to be "a great exchange" as well; God's humanity for humanity's divinity.
The "Great Exchange"
The next appearance of explicit deification language comes in the context of the patristic commonplace of the "great ex-
70. Alister McGrath, Iustitia Dei: A History of the Christian Doctrine of Justification (Cambridge: Cambridge University Press, [1986] 2002), 32.
71. Pedro Urbano López de Meneses, Theosis: La doctrina de la divinización en las tradiciones cristianas: Fundamentos para una teología ecuménica de la gracia (Pamplona: Ediciones Universidad de Navarra, S.A., 2001), 120–21.
72. Jo. eu. tr. 2.13; Rettig, Tractates, 1.70; "Magna beneuolentia! Magna misericordia! Unicus natus est, et noluit manere unus"; CCL 36.17.