Seriously??? Having Saint So-and-so's pinky toe buried under an altar was necessary? It wasn't until the Second Council of Nicaea in 787 which decreed that every altar should contain a relic. Like I said, superstition, gruesome, macabre and creepy. Big money was to be made in duping people into thinking they had "real" body parts of saints and the Catholic Church was often the duper and dupee in the marketing of relics. Later canon law forbid the selling of relics. It was not a practice that God decreed. Though the marking of burial places of the patriarchs was customary to the Jews for the purpose of memorials, desecration of their bodies by dividing them into separate parts to be used as talismans or for protection was something God forbid them to do. It was Almighty God, alone, who protected His people.
Use of relics was not solely a "Christian" thing, though. Numerous religions have the same kind of customs in their history including Buddhism, Hinduism and Islam. Even Marxism and Communism do so to a degree with their veneration of their founders' remains.
According to http://en.wikipedia.org/wiki/Relic:
In ancient Greece, a city or sanctuary might claim to possess, without necessarily displaying, the remains of a venerated hero as a part of hero cult. Other venerable objects associated with the hero were more likely to be on display in sanctuaries, such as spears, shields, or other weaponry; chariots, ships or figureheads; furniture such as chairs or tripods; and clothing. The sanctuary of the Leucippides at Sparta claimed to display the egg of Leda.
Amphora depicting Greek hero cult in honor of Oedipus (Apulian red-figure, 380–370 BC)In contrast to the relics of Christian saints, the bones were not regarded as holding a particular power derived from the hero, with some exceptions, such as the divine shoulder of Pelops held at Olympia. Miracles and healing were not regularly attributed to them; rather, their presence was meant to serve a tutelary function, as the tomb of Oedipus was said to protect Athens.
The bones of Orestes and Theseus were supposed to have been stolen or removed from their original resting place and reburied. On the advice of the Delphic Oracle, the Spartans searched for the bones of Orestes and brought them home, without which they had been told they could not expect victory in their war against the neighboring Tegeans. Plutarch says that the Athenians were likewise instructed by the oracle to locate and steal the relics of Theseus from the Dolopians:
The body of the legendary Eurystheus was also supposed to protect Athens from enemy attack, and in Thebes, that of the prophet Amphiaraus, whose cult was oracular and healing. Plutarch narrates transferrals similar to that of Theseus for the bodies of the historical Demetrius I of Macedon and Phocion the Good which in many details anticipate Christian practice. The bones or ashes of Aesculapius at Epidaurus, and of Perdiccas I at Macedon, were treated with the deepest veneration.
As with the relics of Theseus, the bones are sometimes described in literary sources as gigantic, an indication of the hero's "larger than life" status. On the basis of their reported size, it has been conjectured that such bones were those of prehistoric creatures, the startling discovery of which may have prompted the sanctifying of the site.
The head of the poet-prophet Orpheus was supposed to have been transported to Lesbos, where it was enshrined and visited as an oracle. The 2nd-century geographer Pausanias reported that the bones of Orpheus were kept in a stone vase displayed on a pillar near Dion, his place of death and a major religious center. These too were regarded as having oracular power, which might be accessed through dreaming in a ritual of incubation. The accidental exposure of the bones brought a disaster upon the town of Libretha, whence the people of Dion had transferred the relics to their own keeping.
According to the Chronicon Paschale, the bones of the Persian Zoroaster were venerated, but the tradition of Zoroastrianism and its scriptures offer no support of this.
In religion, a relic is a part of the body of a saint or a venerated person, or else another type of ancient religious object, carefully preserved for purposes of veneration or as a touchable or tangible memorial. Relics are an important aspect of some forms of Buddhism, Christianity, Hinduism, Shamanism, and many other religions. The word relic comes from the Latin reliquiae, meaning "remains" or "something left behind" (the same root as relinquish). A reliquary is a shrine that houses one or more religious relics.
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.
You answered your own question. After the Second Council of Nicaea it became a legal obligation; doesn't mean it was not a custom all the time before that. As your lengthy quote form Wikipedia shows, veneration of relics is a custom that predates Christianity.
More relevant to us is what the Early Church taught.
Few points of faith can be more satisfactorily traced back to the earliest ages of Christianity than the veneration of relics. The classical instance is to be found in the letter written by the inhabitants of Smyrna, about 156, describing the death of St. Polycarp. After he had been burnt at the stake, we are told that his faithful disciples wished to carry off his remains, but the Jews urged the Roman officer to refuse his consent for fear that the Christians "would only abandon the Crucified One and begin to worship this man". Eventually, however, as the Smyrnaeans say, "we took up his bones, which are more valuable than precious stones and finer than refined gold, and laid them in a suitable place, where the Lord will permit us to gather ourselves together, as we are able, in gladness and joy, and to celebrate the birthday of his martyrdom." This is the keynote which is echoed in a multitude of similar passages...
Curiously, in the Apostolic constitutions (ca AD 400) we find admonition against girly squeamishness such as yours:
Section 6 [Conclusion] of the WorkThat It is the Custom of Jews and Gentiles to Observe Natural Purgations, and to Abominate the Remains of the Dead; But that All This is Contrary to Christianity.
XXX . Do not therefore keep any such observances about legal and natural purgations, as thinking you are defiled by them. Neither do you seek after Jewish separations, or perpetual washings, or purifications upon the touch of a dead body. But without such observations assemble in the dormitories, reading the holy books, and singing for the martyrs which are fallen asleep, and for all the saints from the beginning of the world, and for your brethren that are asleep in the Lord, and offer the acceptable Eucharist, the representation of the royal body of Christ, both in your churches and in the dormitories; and in the funerals of the departed, accompany them with singing, if they were faithful in Christ. For precious in the sight of the Lord is the death of His saints. And again: O my soul, return unto your rest, for the Lord has done you good. And elsewhere: The memory of the just is with encomiums (Proverbs 10:7). And, The souls of the righteous are in the hands of God (Wisdom 3:1). For those that have believed in God, although they are asleep, are not dead. For our Saviour says to the Sadducees: But concerning the resurrection of the dead, have you not read that which is written, I am the God of Abraham, and the God of Isaac, and the God of Jacob? God, therefore, is not the God of the dead, but of the living; for all live to Him (Exodus 3:6; Luke 20:38). Wherefore, of those that live with God, even their very relics are not without honour. For even Elisha the prophet, after he was fallen asleep, raised up a dead man who was slain by the pirates of Syria. For his body touched the bones of Elisha, and he arose and revived. Now this would not have happened unless the body of Elisha were holy. And chaste Joseph embraced Jacob after he was dead upon his bed; and Moses and Joshua the son of Nun carried away the relics of Joseph, and did not esteem it a defilement. Whence you also, O bishops, and the rest, who without such observances touch the departed, ought not to think yourselves defiled. Nor abhor the relics of such persons, but avoid such observances, for they are foolish. And adorn yourselves with holiness and chastity, that you may become partakers of immortality, and partners of the kingdom of God, and may receive the promise of God, and may rest for ever, through Jesus Christ our Saviour.
Use of relics was not solely a "Christian" thing, though
Indeed. It is normal element of veneration of anyone held holy. So perhaps, the world should pay less attention to what Protestant vandals find "macabre" and "creepy" and instead worship God properly?