Exodus 13:19 "And Moses took Joseph's bones with him: because he had adjured the children of Israel, saying: God shall visit you, carry out my bones from hence with you."
2 Kings 13:20-21 "And Eliseus died, and they buried him. And the rovers from Moab came into the land the same year. And some that were burying a man, saw the rovers, and cast the body into the sepulchre of Eliseus. And when it had touched the bones of Eliseus, the man came to life and stood upon his feet."
Matthew 9:20-22 "And behold a woman who was troubled with an issue of blood twelve years, came behind him, and touched the hem of his garment. For she said within herself: If I shall touch only his garment, I shall be healed. But Jesus turning and seeing her, said: Be of good heart, daughter, thy faith hath made thee whole. And the woman was made whole from that hour."
Acts 19:11-12 "And God wrought by the hand of Paul more than common miracles. So that even there were brought from his body to the sick, handkerchiefs and aprons: and the diseases departed from them: and the wicked spirits went out of them."
History
(Taken from Wikipedia.Org) In the early church the disturbance, let alone the division, of the remains of martyrs and other saints, was not practiced. They were allowed to remain in their often unidentified resting places in cemeteries and the catacombs of Rome until the earliest recorded removal, or translation of saintly remains was that of Saint Babylas at Antioch in 354, but, partly perhaps because Constantinople lacked the many saintly graves of Rome, they soon became common in the Eastern Empire, though still prohibited in the West. Since the beginning of Christianity, individuals have seen relics as a way to come closer to the saints and thus form a closer bond with God. Since Christians during the Middle Ages often took pilgrimages to shrines of holy people, relics became a large business. The pilgrims saw the purchasing of a relic as a means, in a small way, to bring the shrine back with him or her on returning home, since during the Middle Ages the concept of physical proximity to the "holy" (tombs of saints or their personal objects) was considered extremely important. Instead of having to travel hundreds of miles to become near to a venerated saint, one could venerate the relics of the saint within one's own home.
Treatment of Relics
Crucifixion Nail of Jesus
_Canon
Law 1190
§1 It is absolutely wrong to sell sacred relics.
§2 Distinguished relics, and others which are held in great veneration
by the people, may not validly be in any way alienated nor transferred
on a permanent basis, without the permission of the Apostolic See.
(Purchasing relics, however, is not forbidden by Canon Law if the purchase is meant to prevent the sacred relics from falling into the wrong hands and possible desecration.)