Matteo 7:6

An additional counsel: Give not that which is holy unto the dogs, neither cast ye your pearls before swine, lest they trample them under their feet, and turn again and rend you.

Moral criticism is necessary, religious teaching cannot be discarded. But it would be the height of folly and the very contrary of unauthorized judging to unload one's religious beliefs and experiences, tender sentiments, moral convictions, on any one that comes along, no matter in what condition he might be. For Christians especially the sacred doctrines of Christ are the precious pearls on the ring of His mercy.

To cast these before dogs and swine, before people to whom nothing is sacred, that blaspheme everything holy, is to expose the most sacred beauty to coarseness. And the result is that those very people are encouraged to profane the holy name of God, to think it a proper subject of blasphemous attacks. And it cannot fail: some of the mud will spatter on him that lacked judgment; he will be responsible for the desecration, and therefore also guilty before God. Note the figure of speech used by the Lord, the second verb referring to the first subject, and the first verb to the second subject.