14 This grace was not in the Old Testament, because the law threatened, did not bring aid; commanded, did not heal; made manifest, but did not take away our feebleness: but it prepared the way for that Physician who was to come with grace and truth; as a physician who, about to come to any one to cure him, might first send his servant that he might find the sick man bound. He was not sound; he did not wish to be made sound and lest he should be made sound, he boasted that he was so. The law was sent, it bound him; he finds himself accused, now, he exclaims against the bandage. The Lord comes, cures with somewhat bitter and sharp medicines: for He says to the sick, Bear; He says, Endure; He says, Love not the world, have patience, let the fire of continence cure you, let your wounds endure the sword of persecutions. Were you greatly terrified although bound? He, free and unbound, drank what He gave to you; He first suffered that He might console you, saying, as it were, that which you fear to suffer for yourself, I first suffer for you. This is grace, and great grace. Who can praise it in a worthy manner?
Source: Tractates on the Gospel of John (New Advent)