7 Let not then, brethren, the expectations of your Charity drive me to attempt the task of penetrating into such a deep, of sounding such an abyss, of searching into what is unsearchable. I own my own little measure of ability, and I think I have some perception of yours also, as equally small. This is too high for my stature, and too strong for my strength; and for yours also, I think. Let us, therefore, listen together to the admonition and to the words of Scripture: “Seek not out the things that are too high for you, neither search the things that are above your strength.” Not that such things are forbidden us, since the divine Master says, “There is nothing hid that shall not be revealed:” but if we walk up to the measure of our present attainments, then, as the apostle tells us, not only what we know not and ought to know, but also if we are minded to know anything else, God will reveal even this unto us. But if we have reached the pathway of faith, let us keep to it with all constancy: let it be our guide to the chamber of the King, in whom are hid all the treasures of wisdom and knowledge. For it was in no spirit of grudging that the Lord Jesus Christ Himself acted towards those great and specially chosen disciples of His, when He said, “I have many things to say unto you, but you cannot bear them now.” We must be walking, making progress, and growing, that our hearts may become fit to receive the things which we cannot receive at present. And if the last day shall find us sufficiently advanced, we shall then learn what here we were unable to know.
Source: Tractates on the Gospel of John (New Advent)