Chastity practiced in its perfection makes man live in mortal flesh a spiritual life which is like the prelude of eternal life. Since it frees man from matter, it makes him in a manner like the angels. It even has for its effect to make his body increasingly like the soul, and the soul more and more like to God.
When the body lives only for the soul, it tends in fact to resemble it. The soul is a spiritual substance that can be seen immediately only by the spiritual gaze of God and the angels. It is simple because it has no extended parts; it is beautiful, especially when it keeps a continually upright intention, beautiful with the beauty of beautiful doctrines, of beautiful actions; it is calm, in the sense that it is above every corporeal movement; it is incorruptible or immortal because it is simple and immaterial, because it does not depend intrinsically on a perishable body.
By purity the body becomes spiritual, so to speak; from time to time it lets the soul shine through the gaze especially, like the look of a saint in prayer. By this virtue the body becomes simple: in proportion as the attitude of a worldly woman is complex, in the same proportion that of a virgin is simple. As someone has said: “There are two very simple beings: the child, who does not yet know evil; and the saint, who has forgotten it by dint of conquering it.” By purity the body grows beautiful, for all that is pure is beautiful: for example, an unclouded sky, a diamond through which light passes without any hindrance. Thus the bodies of the saints represented in the frescoes of Fra Angelico have a supernatural beauty which is that of a soul given entirely to God. By purity the body becomes calm and, in a certain way, even incorruptible; whereas vice withers, ravages, and kills the body prematurely, virginity preserves it.
Fr. Reginald Garrigou-Lagrange, O.P., The Three Ages of the Interior Life, (St. Louis: B. Herder Book Co., 1948), p.111.