23 We must proceed by a different path, for our purpose is not the praise of virginity but its preservation. To know that it is a good thing is not enough: when we have chosen it we must guard it with jealous care. The first only requires judgment, and we share it with many; the second calls for toil, and few compete with us in it. “He that shall endure unto the end,” the Lord says, “the same shall be saved,” and “many are called but few are chosen.” Therefore I conjure you before God and Jesus Christ and His elect angels to guard that which you have received, not readily exposing to the public gaze the vessels of the Lord's temple (which only the priests are by right allowed to see), that no profane person may look upon God's sanctuary.
Uzzah, when he touched the ark which it was not lawful to touch, was struck down suddenly by death. And assuredly no gold or silver vessel was ever so dear to God as is the temple of a virgin's body. The shadow went before, but now the reality has come. You indeed may speak in all simplicity, and from motives of amiability may treat with courtesy the veriest strangers, but unchaste eyes see nothing aright. They fail to appreciate the beauty of the soul, and only value that of the body.
Hezekiah showed God's treasure to the Assyrians, who ought never to have seen what they were sure to covet. The consequence was that Judæa was torn by continual wars, and that the very first things carried away to Babylon were these vessels of the Lord. We find Belshazzar at his feast and among his concubines (vice always glories in defiling what is noble) drinking out of these sacred cups.
Source: Letters (New Advent)