19 I have spoken of the power: look now to the meaning. It is a great criminal that is signified by that four days' death and burial. Why is it, then, that Christ troubles Himself, but to intimate to you how you ought to be troubled, when weighed down and crushed by so great a mass of iniquity? For here you have been looking to yourself, been seeing your own guilt, been reckoning for yourself: I have done this, and God has spared me; I have committed this, and He has borne with me; I have heard the gospel, and despised it; I have been baptized, and returned again to the same course: what am I doing?
Whither am I going? How shall I escape? When you speak thus, Christ is already groaning; for your faith is groaning. In the voice of one who groans thus, there comes to light the hope of his rising again. If such faith is within, there is Christ groaning; for if there is faith in us, Christ is in us. For what else says the apostle: “That Christ may dwell in your hearts by faith.” Therefore your faith in Christ is Christ Himself in your heart. This is why He slept in the ship; and why, when His disciples were in danger and already on the verge of shipwreck, they came to Him and awoke Him.
Christ arose, laid His commands on the winds and waves, and there ensued a great calm. So also with you; the winds enter your heart, that is, where you sail, where you pass along this life as a stormy and dangerous sea; the winds enter, the billows rise and toss your vessel. What are the winds? You have received some insult, and are angry: that insult is the wind; that anger, the waves. You are in danger, you prepare to reply, to render cursing for cursing, and your vessel is already near to shipwreck.
Awake the Christ who is sleeping. For you are in commotion, and making ready to render evil for evil, because Christ is sleeping in your vessel. For the sleep of Christ in your heart is the forgetfulness of faith. But if you arouse Christ, that is, recallest your faith, what do you hear said to you by Christ, when now awake in your heart? I [He says] have heard it said to me, “You have a devil,” and I have prayed for them. The Lord hears and suffers; the servant hears and is angry!
But you wish to be avenged. Why so? I am already avenged. When your faith so speaks to you, command is exercised, as it were, over the winds and waves, and there is a great calm. As, then, to awaken Christ in the vessel is just to awaken faith; so in the heart of one who is pressed down by a great mass and habit of sin, in the heart of the man who has been a transgressor even of the holy gospel and a despiser of eternal punishment, let Christ groan, let such a man betake himself to self-accusation.
Hear still more: Christ wept; let man bemoan himself. For why did Christ weep, but to teach man to weep? Wherefore did He groan and trouble Himself, but to intimate that the faith of one who has just cause to be displeased with himself ought to be in a sense groaning over the accusation of wicked works, to the end that the habit of sinning may give way to the vehemence of penitential sorrow?
Source: Tractates on the Gospel of John (New Advent)