Angels are pure spirit; animals and plants are purely physical matter. Our glory is to unite the material and the spiritual within our own person. Jesus crowns this human glory in the Incarnation.
There is a tendency today to conclude that when a person dies he is no longer here; he has gone away to Heaven, Purgatory or Hell. That is not entirely true. Through the body, something of the deceased person remains here.
Excavations of St. Peter’s tomb revealed an ancient Greek inscription on the wall which said, “Peter is here.” Though his soul has gone to God, what remains of his body is still here. Peter is not simply his soul; he is also his body. So yes, Peter is “here.” To revere St. Peter’s body and smaller relics of it is to revere him and have something of him here with us.
Relics and reverence for the bodies of the dead anchor us in this truth about ourselves: we are matter and spirit, body and soul.
During my recent pilgrimage we visited the saints; we spent time near their bodies. Peter is here; so is Cecilia; Monica and Mark are, too. They are with God and they are also still with us. In my own parish I have nearly a dozen small relics of the saints…. this is reverence, so as to remember and experience their presence, not their absence. Peter is with God and Peter is still here!
—from the National Catholic Register article ‘Peter Is Here’: What Every Catholic Should Know About Relics and the Human Body by Msgr. Charles Pope