Relics are the remains of a saint. They are classified according to degrees. First degree relics are physical remains of a saint. They are most typically bones. Second degree relics are objects or items that touched a saint while he was alive. The relics of Christ's Passion would be second degree relics. Third degree relics include anything that touched other relics. Normally, it is the bones of the saints and the relics of Christ's Passion that are mentioned among the relics.
Protestants do not like relics. Most of all, they oppose the idea that grace is conferred through them. When they hear that Catholics seek miracles through relics, they say Catholics claim relics are magical. But something that is magical is the cause of miracles, while relics have no such power. Relics are sometimes the instrument that God uses to cure others, the occasions of God's miracles, but there is nothing miraculous in the relic itself. The Catholic Church acknowledges this.
And relics have been the occasions of God's miracles. Elisha's bones brought a dead man back to life: "So Elisha died, and they buried him. Now bands of Moabites used to invade the land in the spring of the year. And as a man was being buried, lo, a marauding band was seen and the man was cast into the grave of Elisha; and as soon as the man touched the bones of Elisha, he revived, and stood on his feet" (2 Kgs. 13:20-21). The cloak of Christ was the occasion of a miracle (Matt. 9:20-22), as was Peter's shadow (Acts 5:15-16) and Paul's handkerchief (Acts 19:11-12).
Protestants argue that many different places often claim the relics of the same saint. Therefore, most relics must be frauds. Of course, through the ages, relics were broken, divided, and sent to many places, so it is not unusual to have the bones of the same saint found in many different locations.
Protestants like to repeat the old joke that if the pieces of the True Cross were gathered together, you would have enough wood to build a warship. Thus, they say, most relics are fake. But in the nineteenth century, a Frenchman named Rohault de Fleury, calculated that if all the relics of the true cross that were known to exist (including those that there was record of but had been lost) were put together, it would not even make half a cross.
Are most relics fake? Some are, but with most relics, there is good reason to believe that they are authentic, because the relics were always in the possession of a church or church member, and passed down faithfully. Some relics are almost assuredly authentic. Some are probably authentic. Some are doubtful. And some are fake. Does this matter? Relics work to inspire faith and aid in the devotion given to saints. To some it is a matter of curiosity. If the believer thinks the relic is authentic, but it is not, no harm is done. What he does not know will not bother him.
And then there is the Biblical example of the veneration of relics–that of Christ Himself. Joseph of Arimathea removed the body of Christ from the cross after valiantly asking Pilate for the body (Mark 15:43; John 19:38), and he buried him in his own, newly made tomb (Matt. 27:60). Nicodemus brought one hundred pounds of spices to use on the body (John 19:39). Afterwards, the women went to the tomb (Matt. 28:1) and anoint the body of Christ further (Mark 16:1; Luke 24:1). Thus, the body of Christ–the ultimate of all relics–was venerated by His disciples.
Martyrdom of Polycarp (Martyrdom of Polycarp 17,18 [A.D. 157]) "Accordingly, we afterwards took up his bones, as being more precious than the most exquisite jewels, and more purified than gold, and deposited them in a fitting place, whither, being gathered together, as opportunity is allowed us, with joy and rejoicing, the Lord shall grant us to celebrate the anniversary of his martyrdom."
Basil (Epistle 197 [A.D. 375]) "These relics do you receive with a joy equivalent to the distress with which their custodians have parted with them . . . These bones He will crown, together with that soul, in the righteous day of His requital".
Ambrose (Epistle 22, 2-17 [A.D. 380]) "On the following day we translated the relics to the basilica called Ambrosian. During the translation a blind man was healed . . . He declares that when he touched the hem of the robe of the martyrs, wherewith the sacred relics were covered, his sight was restored.
Jerome (Epistle 109:1 [A.D. 404]) "Still we honour the relics of the martyrs, that we may adore Him whose martyrs they are . . . I ask Vigilantius, Are the relics of Peter and of Paul unclean? . . . And do we, every time that we enter the basilicas of apostles and prophets and martyrs, pay homage to the shrines of idols?"
Augustine (City of God, 22:8 [A.D. 413]) "Lucillus bishop of Sinita, in the neighborhood of the colonial town of Hippo, was carrying in procession some relics of [Stephen], which had been deposited in the castle of Sinita . . . Eucharius, a Spanish priest, residing at Calama, was for a long time a sufferer from stone. By the relics of the same martyr, which the bishop Possidius brought him, he was cured. Afterwards the same priest, sinking under another disease, was lying dead, and already they were binding his hands. By the succor of the same martyr he was raised to life, the priest's cloak having been brought from the oratory and laid upon the corpse."
Theodoret of Cyrus (The Cure of Pagan Maladies, 8:54 [A.D. 449]) "Though the body has been divided, its grace has continued undivided. And that little particle and smallest relic has the same power as the absolutely and utterly undivided martyr."