The gospel tells us how Christ the Lord walked upon the waters of the sea, and how the apostle Peter did the same until fear made him falter and lose confidence. Then he began to sink and emerged from the water only after calling on the Lord with renewed faith.
Now we must regard the sea as a symbol of the present world, and the apostle Peter as a symbol of the one and only Church. For Peter, who ranked first among the apostles and was always the most ready to declare his love for Christ, often acted as spokesman for them all. For instance, when the Lord Jesus Christ asked who people thought he was and the other disciples had cited various opinions, it was Peter who responded to the Lord’s further question, “But who do you say I am?” with the affirmation: “You are the Christ, the Son of the living God.” One replied for all because all were united.
When we consider Peter as a representative member of the Church we should distinguish between what was due to God’s action in him and what was attributable to himself. Then we ourselves shall not falter; then we shall be founded upon rock and remain firm and unmoved in the face of the wind, rain, and floods, which are the trials and temptations of this present world. Look at Peter, who in this episode is an image of ourselves; at one moment he is all confidence, at the next all uncertainty and doubt; now he professes faith in the immortal One, now he fears for his life.
“Lord, if it is you, bid me come to you upon the water.” When the Lord said “Come” Peter climbed out of the boat and began to walk on the water. This is what he could do through the power of the Lord; what by himself? “Realizing how violently the wind was blowing, he lost his nerve, and as he began to sink he called out, ‘Lord, I am drowning, save me!'”
When he counted on the Lord’s help it enabled him to walk on the water; when human frailty made him falter he turned once more to the Lord, who immediately stretched out his hand to help him, raised him up as he was sinking, and rebuked him for his lack of faith.
Think, then, of this world as a sea, whipped up to tempestuous heights by violent winds. A person’s own private tempest will be his or her unruly desires. If you love God you will have power to walk upon the waters, and all the world’s swell and turmoil will remain beneath your feet. But if you love the world it will surely engulf you, for it always devours its lovers, never sustains them. If you feel your foot slipping beneath you, if you become a prey to doubt or realize that you are losing control, if, in a word, you begin to sink, say: “Lord, I am drowning, save me!”
Only he who for your sake died in your fallen nature can save you from the death inherent in that fallen nature.
St Augustine of Hippo