Father Cassilly comments on the Psalmist’s declaration “Ye are gods” (Ps 81:6) and its awesome implication that the just man shares in the Divine nature. He notes that theologians “explain that the grace which makes man share the Divine nature is but an image or representation of the Godhead. This explanation they glean from Genesis (1:26), where it is said that man was created to the image and likeness of God. St. Thomas, commenting on the expression, ‘to the image,’ says it means an approach to God, and not equality with Him.”
“However, this imaging forth of God in the sanctified soul is a closer approximation to the Deity than anything we can dream or imagine here on earth. Even he of the eagle eye, St. John, despaired of comprehending it when he said, ‘Dearly beloved, we are now the sons of God; and it hath not yet appeared what we shall be. We know that when He shall appear, we shall be like to Him, because we shall see Him as He is.'” (1 Jn 3:2)
Father Cassilly remarks: “No wonder the Fathers of the Church, carried away by ardor and enthusiasm, speak of sanctifying grace as the ‘deification’ of the soul, and say that we partake of the Divinity as the molten iron of fire, as the air of sunshine.” For example, St. Basil says: “As bright and translucent bodies, when touched by the rays of the sun, become themselves brilliant above measure and a new source of light; so also souls, breathed upon and illumined by the Spirit, themselves become filled with the Spirit and send forth grace to others. . . . Hence is your likeness to God.” (De Spiritu Sancto, 9) And St. Gregory of Nyssa remarks: “The Spirit has life in Himself, and they who share in it live in a divine way, having a divine and heavenly life.” (Contra Eunomium, 1, 5)
And St. Thomas Aquinas states: “Only God can deify by communicating participation with the Divine nature through a certain sharing of His likeness; as it is impossible that anything but fire should ignify.” (Summa Theologica I-II, 112, 1)
Quotations from Francis Cassilly, A Story of Love, 2d ed. (St. Louis: B. Herder, 1917).