Top portion of a "Letter from Heaven," produced in England, 18th century

Himmelsbriefe: Heaven-Sent Chain Letters

For more than a thousand years, people have used letters allegedly written by Christ as both doctrinal evidence and magical charms.
An abbey cellarer testing his wine. Illumination from a copy of Li livres dou santé by Aldobrandino of Siena, late 13th century

When Monks Went Undercover to Steal Relics

Because relics were understood to be capable of working miracles, any relic that was stolen must have wanted to be.