From Letter V (ca. 450)
In all these things they entangle themselves in an inextricable maze, not listening to the apostle when he says, “See that no one deceive you through philosophy and vain deceit after the tradition of men, after the rudiments of the world, and not after Christ; for in him dwells all the fulness of the Godhead bodily, and in him you are made full, who is the head of every principality and power.” And again: “let no man beguile you by a voluntary humility and worshipping of angels, treading on things which he has not seen, vainly puffed up by the senses of his flesh, not holding fast the head from whom all the body, being supplied and knit together through the joints and bands, increases with the increase of God.”
What then is the use of admitting into the heart what the law has not taught, prophecy has not sung, the truth of the Gospel has not proclaimed, the apostles’ teaching has not handed down? But these things are suited to the minds of those of whom the apostle Paul speaks, “For the time will come when they will not endure sound doctrine, but having itching ears, will heap to themselves teachers after their own lusts, and they will turn away indeed their hearing from the truth, and turn aside unto fables.” And so we can have nothing in common with men who dare to teach or believe such things, and strive by any means in their power to persuade men that the substance of flesh is foreign to the hope of resurrection, and so break down the whole mystery of Christ’s incarnation: because it was wrong for Christ to take upon him complete humanity if it was wrong for him to emancipate complete humanity.
St. Leo the Great (ca. 400-461) was a Roman cleric and theologian. He served as a diplomat for the papal court and became Bishop of Rome in 440, exercising pastoral care during the depredations of the Huns and the Vandals. Letter V was a message of encouragement sent to St. Tiburius of Astorga, who was engaged in conflict with Priscillianist heretics. Leo’s feast day is November 10.