Answer
The Roman Catholic and Eastern Orthodox churches believe that the dead bodies of some of the saints remain miraculously incorruptible, that is, their bodies do not decay as the corpses of “normal” people would. Catholics claim that these saints’ bodies are supernaturally preserved as a fulfillment of Psalm 16:10, “Thou wilt not . . . give thy holy one to see corruption” (Douay-Rheims Bible).
Some of these “incorruptible” bodies of saints are on display in various churches and monasteries around the world. Invariably, the bodies are enshrined, and worshipers and pilgrims pay homage to the remains. There is a lengthy list of saints, including St. Silvan, St. Teresa Margaret, and St. Bernadette of Lourdes, who, after their deaths, were officially declared “incorrupt” by the Catholic Church, which means that their remains were showing little to no decomposition, or at least delayed decomposition.
Of course, a slow rate of decay is not the same as miraculous incorruptibility. Decomposition of a body depends on some external and internal environmental factors, such as the amount of oxygen and moisture to which the corpse is exposed, the ambient temperature, and the presence of various bacteria. A body encased within a dry, airtight coffin in a cold tomb will decay much more slowly than a body exposed to the elements. Nevertheless, every dead thing eventually decays, be it saint, snail, or snapdragon. The Roman Catholic Church knows this full well and takes great care to preserve the appearance of the dead saints they keep in their buildings—many of the “incorruptible” bodies have been fitted with wax masks and hand coverings to hide the fact that decomposition has indeed been occurring. A pilgrim to Lourdes to see St. Bernadette, for example, may as well be visiting a wax museum.
The bodies declared “incorrupt” by the Catholic Church have indeed seemed to decompose more slowly than normal, even without the wax touch-ups. But, again, slow decay is not necessarily miraculous. A man or woman thought to be headed for sainthood would likely have received a better coffin and a better tomb than the average person. This would greatly contribute to the preservation of the body and lead to a subsequent misunderstanding about incorruptibility.
If the body of an “incorruptible saint” was truly miraculously incorruptible, it would not need to be kept in an airtight and climate-controlled case.
The Catholic Church’s emphasis on physicality—relics, corpses, transubstantiation, icons, beads, statues, etc.—leads many away from the spiritual matters of the heart. And their fascination with the “holy” saints shifts the focus from Christ. Psalm 16:10 is a prophecy of Christ, the only holy (i.e., sinless) person ever to have lived. Jesus, the Holy One of God, truly saw no corruption, having been raised from the dead on the third day after His death.
Those who trust in Christ are promised an incorruptible body some day: “Flesh and blood cannot inherit the kingdom of God; neither doth corruption inherit incorruption. Behold, I shew you a mystery; We shall not all sleep, but we shall all be changed, In a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed. For this corruptible must put on incorruption” (1 Corinthians 15:50–53, KJV). (The word incorruptible is also translated “imperishable” in other translations.) One day, all believers will be glorified, body and soul, both those who have died and those who remain alive at the return of Christ (cf. 1 Thessalonians 4:15–17).
