The Divine Person of Jesus Christ, Who possessed all the fullness of Divine life, and Who at the same time became perfect Man (i.e. man in all things but sin), not only re-establishes in its original purity the image of God defiled by man in his fall (“having refashioned the soiled image to its former estate”),[Kontakion for the Sunday of Orthodoxy] but also conjoins the human nature assumed by Him with the Divine life – “suffused it with Divine beauty”. The Fathers of the VIIth Oecumenical Council say, “He (God) recreated him (man) into immortality by giving him this inalienable gift. This recreation was more in God’s likeness and better than the first creation – this gift is eternal”, the gift of communion with the Divine beauty and glory. Christ, the new Adam, the beginning of the new creature – the heavenly man bearing the Holy Spirit within him – brings man to that aim for which the first Adam was created and from which he turned away through his fall; he brings him to the fulfilment of the design of the Holy Trinity concerning him: “Let us make man according to our own image and likeness” (Gen. i,26). According to this design, man should be not only an image of God, his Creator, but should also bear His likeness. Yet in the description of the accomplished act of creation “And God made man, according to the image of God he made him” (Gen. i,27), nothing is said about likeness. It is given to man as a task, to be fulfilled by the action of the grace of the Holy Spirit, with the free participation of man himself. Freely and consciously, “since the expression ‘according to the image’ indicates capacity of mind and freedom”, man enters into the design of the Holy Trinity concerning him and creates his likeness to God, insofar as is possible for him, “for the expression ‘according to the likeness’ means likeness to God in virtues (perfections)” [St John of Damascus], in this way participating in the work of Divine creation.
Thus, if the Divine Hypostasis of the Son of God became Man, our case is the reverse: man can become god, not by nature, but by grace. God descends in becoming Man; man ascends in becoming god. Assuming the likeness of Christ, he becomes “the temple of the Holy Ghost” which is in him (I Cor. vi, 19), re-establishes his likeness to God. Human nature remains what it is – the nature of a creature; but his person, his hypostasis, by acquiring the grace of the Holy Spirit, by this very fact associates itself with Divine life, thus changing the very being of its creaturely nature. The grace of the Holy Spirit penetrates into his nature, combines with it, fills and transfigures it. Man grows, as it were, into the eternal life, the beginning of deification, which will be made fully manifest in the life to come.
Leonid Ouspensky, “The Meaning and Language of Icons,” in Leonid Ouspensky and Vladimir Lossky, The Meaning of Icons(Saint Vladimir’s Seminary Press, 1983) 34-35.