Question:
Answer:
Ordinarily, a relic exposed for public veneration is authenticated by a cardinal or bishop or other delegated person. This appears to no longer be a strict requirement of canon law as it used to be, but it is still the case that the Church requires that relics publicly venerated be authentic, and authentication by some prelate is still the normal way of proceeding.
By “authentic” is meant that, humanly speaking, the relic comes from credible sources. This does not mean there is strict certainty about the relic but only prudent, human confidence. In the veneration of very ancient relics, their antiquity and identity throughout time provides a credible witness.
Very often in researching very ancient relics, one finds that the claims of tradition are very credible indeed. For example, the bones of St. Peter verified in the twentieth century under the papal altar in the Vatican were identified by the painstaking work of the archeologist Margherita Guarducci. The relics of St. Nicholas in Bari or those of St. Augustine in Pavia are very well attested because of their various solemn translations from place to place. And, of course, the research done on the Holy Shroud of Turin has greatly supported the credibility of the relic.
So we should not be skeptics about relics but rather open to the reliability of tradition. If one or another relic is shown to be false, this should not trouble our faith, since we are dealing here with human judgments, not revelation.