But because on this journey waves and storms of various temptations abound, believe in the one crucified so that your faith can get on that tree. You won’t drown but will be borne by that tree. That’s how in the waves of this world he was sailing who said, “Far be it for me to boast except in the cross of our Lord Jesus Christ” (Gal 6:14). (Sermon 131, 2; PL 38, 730)

There is no one in this world who is not a stranger, even if not all desire to return to their homeland. We suffer floods and storms on this journey, but at least we ought to be in the boat. If there are dangers in the boat, out of the boat there is certain doom. However strong the shoulders of someone swimming in the sea, eventually he’s overcome by the power of the sea and sinks and drowns. We have to be in the boat, then, that is, be borne by wood so we can cross this sea. The wood that bears our weakness is the Lord’s cross, the cross with which we are marked, the cross by which we are protected from drowning in this world. (Augustine, Sermon 75[76], 1; PL 38, 475)

In the second of his sermons on John’s Gospel, Augustine speaks of the difficulty of moving beyond the changeable beings of creatures, including the human soul, in order to reach the unchangeable God who revealed himself to Moses as “He Who Is.”

It’s as if one were to see his homeland from a distance, but with a sea in between: he sees where to go but has no way to get there. So we desire to arrive at a stability of our own where that which is is, because it alone always is as it is, and the sea of this world lies in our way, even though we already see where to go. Many, of course do not even see where to go. That there might be a way for us to go, he has come from him to whom we wished to go. And what has he done? He has arranged for a wood by which we may cross the sea. For no one can cross the sea of this world, unless borne by the cross of Christ. Even someone with weak eyesight sometimes embraces this cross; let anyone who does not see from afar where he is going not depart from the cross, and it will carry him there. 

Therefore, brothers and sisters, I would like to impress this upon your hearts: if you wish to live in a pious and Christian manner: cling to Christ according to what he became for us so that you may arrive at him according to that which he is and according to what he was. He approached so that he might become this for us. For our sake he became that on which the weak may be borne and may cross the sea of this world and reach their homeland where no ship will be needed because there is no sea to cross. It is better, then, not to see with the mind that which is and not to depart from the cross of Christ than to see it with the mind and despise the cross of Christ. Better still it is, and best of all, if possible, both to see where we ought to go and to hold fast to what carries us as we go. This the great minds of the mountains were able to do, the ones who are called mountains, those whom the light of divine justice pre-eminently illuminates: they were able to do this and saw that which is. Because he saw it, John said, “In the beginning was the Word, and the Word was with God, and the Word was God.” They saw this, and in order to reach what they saw from afar, they did not depart from the cross of Christ and did not despise Christ’s lowliness. But little ones who cannot understand this, who do not depart from the cross and passion and resurrection of Christ, are conducted to what they do not see in the same ship on which they who do see also arrive.

But there have in fact been some philosophers of this world who have sought for the Creator by means of the creature; for he can be found by means of the creature, as the apostle plainly says, “For the invisible things of God from the creation of the world are clearly seen, being understood from the things that have been made, even His eternal power and glory; so they are without excuse.” And it follows, “Because when they knew God;” he did not say,” Because they did not know,” but “Because when they knew God, they did not glorify him as God, neither were thankful; but became vain in their imaginations, and their foolish heart was darkened.” How darkened? It follows, when he says more plainly: “Professing themselves to be wise, they became fools” (Rom 1:20-22) They saw where they had to come; but ungrateful to him who gave them what they saw, they wished to ascribe to themselves what they saw; and having become proud, they lost what they saw and were turned from it to idols and images and to the worship of demons, to adore the creature and to despise the Creator. It was men struck down who did those things, and pride that struck them down, the pride that led them to say that they were wise. Those of whom the apostle was speaking--”Who, when they had known God”-- saw what John says, that by the Word of God all things were made. For these things are also found in the books of the philosophers, as also that God has an only-begotten Son by whom are all things.

They were able to see that which is, but they saw it from afar: they were unwilling to hold the lowliness of Christ, on which ship they might have arrived in safety at that which they could see from afar, and the cross of Christ seemed vile to them. The sea has to be crossed, and you despise the wood? Oh, proud wisdom! You laugh and scorn the crucified Christ, even though it is he whom you see from afar: “In the beginning was the Word, and the Word was with God.” But why was he crucified? Because the wood of his humiliation was needed by you. For you had become swollen with pride and had been cast out far from that homeland; and the way there was interrupted by the waves of this world, and there is no way to reach the homeland unless borne by the wood. Ingrate! You laugh and scorn him who came to you so that you could return! He himself became the way, and this through the sea. That is why he walked on the sea (Mt 14:25): to show that there is a way in the sea. But you, who are unable in any way to walk on the sea, be carried in the ship, be carried by the wood: believe in the crucified One, and you shall arrive there. He was crucified for your sake, to teach you humility. (In Ioannem Tr. 2, 2-4; PL 35, 1389-1391)