You inquired about the Patristic idea that the “garments of skins” (Gen. 3:21) God made for Adam and Eve were not merely the furry hides of some animals, but in fact physical bodies, their supralapsarian forms having been of a spiritual, or at least more rarified, order. One of the best studies of this question I know of can be found in Deification in Christ by Panayiotis Nellas (St Vladimir’s, 1987), notably in a section entitled “The ‘Garments of Skin'”.
A number of Fathers interpreted the text along these lines, among them Saints Gregory of Nyssa and Maximos the Confessor. Saint Gregory, for example, has this to say:
“When I hear the word ‘skin’ it conveys to me the form of irrational nature, with which, having become familiar with passion, we have been clothed. It is those things which man took in addition from irrational skin: sexual union, conception, birth, pollution, the nipple, food, excretion, gradual growth to full stature, adult life, old age, sickness, death” (On the Soul and Resurrection).
Understood thus, the “garments of skin” are obviously our own present bodies, subject as they are to disease, degeneration, and death. As for those who may object that this interpretation conflicts with the doctrine of the Resurrection, they need to consult the following passage in the writings of Saint Paul: “As we have borne the image of the earthly, we shall also bear the image of the heavenly. Now this I say, brethren, that flesh and blood cannot inherit the kingdom of God; neither doth corruption inherit incorruption” (1 Cor. 15:49-50).
Keep in mind, Christ being our model, that a “spiritual body” (1 Cor. 15:44) can walk through locked doors (John 20:19).