The following is an excerpt from Fr. Martin von Cochem's The Four Last Things:
Now that we have meditated upon the heavenly Jerusalem, the city of God, we will proceed to consider the happiness which the Saints who dwell therein enjoy, both in regard to body and soul. It is true as yet they have not their bodies, as a general rule, but at the Last Day they will all have them again, and those bodies will then be so beauteous, that nothing in the world can compare with them. And this will principally be because every member will be endowed with four qualities or attributes, namely: beauty, impassibility, agility, and subtlety. By reason of its beauty or glory the body of each one of the elect will shine like a star, yet, as one star differs from another in glory, so the Saints will shine with greater or less splendour, according as their lives upon earth have been more or less holy. In these glorified and radiant bodies the blessed will be so inexpressibly beautiful, that if a mortal man were now to behold one of these resplendent beings, he would be dazzled by its brilliance and be ready to expire for joy of heart.
In her revelations to St. Bridget, the Blessed Mother of God once said: "The Saints stand around my Son like countless stars, whose glory is not to be compared with any temporal light. Believe me, if the Saints could be seen shining with the glory they now possess, no human eye could endure their light all would turn away, dazzled and blinded." Think what happiness it will be for thee, when thy body shines like the sun at midday. Everything that lives and moves rejoices in the light and warmth of the sun: it gladdens all the face of nature. In like manner thy body will be a joy and delight to thyself and all around thee in Heaven, because of its beauty and its glory.
The second attribute is impassibility, for the glorified body is incapable of suffering. It will never be sick or infirm, it will not grow old or unsightly. It will never again be inconvenienced by hunger or thirst, by heat or cold, by draught or dampness. It can nevermore be burned by fire, drowned in water, wounded by the sword or crushed beneath a weight; it will be immortal, unchangeable, eternally endowed with perfect health and unfailing strength. If any one on earth could purchase this gift of impassibility, how gladly would he give all he possessed to obtain it!
The third attribute is agility. The glorified body will be able to traverse the greatest distance with the speed of thought. In one moment it can come down from Heaven to earth; in one moment it can pass from one end of the Heavens to the other, without labour, without fatigue, without difficulty. We often wish that we could fly like the birds, that we could speed on our way like clouds on the wings of the wind, that we could follow thought in its rapid flight. If it were possible to purchase this power, every one would part with all his worldly wealth for it, if only to obtain it for one single year. How is it, then, that thou dost take so little trouble to ensure for thyself the possession of this gift for all eternity?
The fourth attribute of the glorified body is subtlety, which consists in the faculty of penetrating all matter, of passing in and out wheresoever it will. No wall is so thick, no iron gate so massive, no mountain so great as to form an obstacle to the glorified body. As the sun s rays pass through glass, so the bodies of the redeemed as they are in Heaven, penetrate all matter, however dense and solid it may be. They can also make themselves visible or invisible at will. What wouldst thou not give to become possessed of such a faculty? How great is Thy bounty, almighty God, towards Thine elect ! Thou bestowest upon them precious and sublime gifts, that no amount of this world’s riches can purchase. Who would not gladly spend his life in Thy service and suffer afflictions in this world in order to possess these inestimable gifts to all eternity? Ask this poor frail body if it would not fain shine as the light, be exempt from suffering, move with the speed of thought, be unfettered as a spirit? To own such powers would indeed be a joy and a consolation unspeakable. Wouldst thou not consent to have a hard penance laid on thee for a whole year, if at the end these attributes were bestowed on thee?
If so, then do not esteem it a grievance to lead here below a life of penance, in the hope that these fair gifts may be thine during all eternity. See that here on earth thou love the light, the light of good works; bear all pain and tribulation with patience, be prompt and zealous in the service of God; mortify within thyself more and more all sensual desires, and thou wilt assuredly be the happy possessor hereafter of these four attributes of the glorified body.