A few weeks ago I explored the nature of the soul. Created by God at our conception (or at least, very close to our conception), the human soul is never created without the body (always created at the moment of conception).
This is the difference between us and angels. Angels are pure spirits. They never had and never will (as far as we know) have bodies. We do. We start life with our body, leave it upon our death and are reunited with our glorified bodies at the general resurrection.
Our resurrected body is “us,” not some different body. It is the natural “home” for our soul. It is not however, as it appeared at any point during our mortal life. There is much theology on this, but Catholic Answers apologist Father Vincent Serpa explains it succinctly:
The Church teaches that at the resurrection the bodies of the just will be re-modeled and transfigured to the pattern of the risen Christ. Like his body, our resurrected bodies will be those of a person in his prime. They will be incapable of suffering. They will have a spiritual nature – not that they will be pure spirit, but they will be like that of Jesus, who could penetrate closed doors after he had risen. They will have a new agility in that they will be able to obey the soul with great ease and speed – so that when the spirit is willing, the flesh will no longer be weak! Our bodies will be free from all deformity and will reflect God’s beauty to the degree that our souls do.
Our souls are unique and so is our body. Both are a gift from God. In our mortal state, each body has unique, lifelong DNA from the moment of conception. It is intertwined with and tightly united to our soul. It is the physical temple of the Holy Spirit, belonging to Christ and not our own to use or abuse however we please.
Proper respect for our body means we will care for it as best we are able (hygiene, healthcare, nutrition, exercise, etc.). Likewise, our body is not a sexual playground. We are to live modest, chaste lives – sharing the gift of our body with no one other than a spouse.
Finally, when our mortal body dies, dignity and respect must continue. It must be buried or interred within a mausoleum. Cremation is permissible, but under no circumstance may remains be scattered, turned into jewelry or the like.
The human body shares in the dignity of “the image of God”: it is a human body precisely because it is animated by a spiritual soul, and it is the whole human person that is intended to become, in the body of Christ, a temple of the Spirit:
Man, though made of body and soul, is a unity. Through his very bodily condition he sums up in himself the elements of the material world. Through him they are thus brought to their highest perfection and can raise their voice in praise freely given to the Creator. For this reason man may not despise his bodily life. Rather he is obliged to regard his body as good and to hold it in honor since God has created it and will raise it up on the last day.