"Before the transgression, Adam shared in divine illumination and brilliance. He was clothed in the true robe of glory and was not naked, nor was he ugly in his nakedness, but was truly unspeakably better adorned than those who wear diadems embellished with much gold and precious stones. When our human nature was stripped of this divine illumination and radiance as a result of the ugly transgression, the Word of God had mercy on this nature and in His compassion took it upon Himself. On Mount Tabor He showed it clothed once more to His chosen disciples (cf. Lk. 9:28-37), proving to all what we had once been, and what those of us who believed in Him and attained to perfection in Him would be through Him in the age to come. You will find that the earnest of this perfection of those who live according to Christ is openly given here and now to God's saints. They reap, so to speak, the good of the age to come."
St. Gregory Palamas, The Homilies Vol. 1 (St. Tikhon's Seminary Press) pg. 207