13 If any one in a city had some bodily sickness, and there was in that place some very skilful physician who was an enemy to the sick man's powerful friends; if any one, I say, in a city were labouring under some dangerous bodily sickness; and there was in the same city a very skilful physician, an enemy as I said, of the sick man's powerful friends, and they were to say to their friend, “Do not call him in, he knows nothing;” and they were to say this not from any judgment of their mind, but through dislike of him; would he not for his own safety's sake remove from him the groundless assertions of his powerful friends, and with whatever offense to them, in order that he might live but a few days longer, call that physician in, whom common report had given out as most skilful to drive away the disease of his body?
Well, the whole race of mankind is sick, not with diseases of the body, but with sin. There lies one great patient from East to West throughout the world. To cure this great patient came the Almighty Physician down. He humbled Himself even to mortal flesh, as it were to the sick man's bed. Precepts of health He gives, and is despised; they who do observe them are delivered. He is despised, when powerful friends say, “He knows nothing.” If He knew nothing, His power would not fill the nations.
If He knew nothing, He would not have been, before He was with us. If He knew nothing, He would not have sent the Prophets before Him. Are not those things which were foretold of old, fulfilled now? Does not this Physician prove the power of His art by the accomplishment of His promises? Are not deadly errors overturned throughout the whole world; and by the threshing of the world lusts subdued? Let no one say, “The world was better aforetime than now; ever since that Physician began to exercise His art, many dreadful things we witness here.” Marvel not at this? Before that any were in course of healing, the Physician's residence seemed clean of blood; but now rather as seeing what you do, shake off all vain delights, and come to the Physician, it is the time of healing, not of pleasure.
Source: Sermons on Selected Lessons of the New Testament (New Advent)