Text from St. John of the Cross, Spiritual Canticle, Stanza XII:
The soul now conscious of a vehement longing after God, like a stone rushing to its center, and like wax which has begun to receive the impression of the seal which it cannot perfectly represent, and knowing, moreover, that it is like a picture lightly sketched, crying for the artist to finish his work, and having its faith so clear as to trace most distinctly certain divine glimpses of the majesty of God, knows not what else to do but to turn inward to that faith — as involving and veiling the face and beauty of the Beloved — from which it has received those impressions and pledges of love, and which it thus addresses:
O crystal well!
O that on Your silvered surface
You would mirror forth at once
Those desired eyes
Which are outlined in my heart.
The soul vehemently desiring to be united to the Bridegroom, and seeing that there is no help or succor in created things, turns towards the faith, as to that which gives it the most vivid vision of the Beloved, and adopts it as the means to that end. And, indeed, there is no other way of attaining to true union, to the spiritual betrothal of God, according to the words of Hosea: “I will betrothe you to Me in faith.” In this fervent desire it cries out in the words of this stanza, which are in effect this: “O faith of Christ, my Bridegroom! Oh that you would manifest clearly those truths concerning the Beloved, secretly and obscurely infused — for faith is, as theologians say, an obscure habit — so that your informal and obscure communications may be in a moment clear; Oh that you would withdraw yourself formally and completely from these truths — for faith is a veil over the truths of God — and reveal them perfectly in glory.” Accordingly it says:
“O crystal well!”
2. Faith is called crystal for two reasons: because it is of Christ the Bridegroom; because it has the property of crystal, pure in its truths, a limpid well clear of error, and of natural forms. It is a well because the waters of all spiritual goodness flow from it into the soul. Christ our Lord, speaking to the woman of Samaria, calls faith a well, saying, “The water that I will give him shall become in him a well of water springing up into life everlasting.” This water is the Spirit which they who believe shall receive by faith in Him. “Now this He said of the Spirit which they who believed in Him should receive.”
“Oh that on your silvered surface.”
3. The articles and definitions of the faith are called silvered surfaces. In order to understand these words and those that follow, we must know that faith is compared to silver because of the propositions it teaches us, the truth and substance it involves being compared to gold. This very substance which we now believe, hidden behind the silver veil of faith, we shall clearly behold and enjoy hereafter; the gold of faith shall be made manifest. Hence the Psalmist, speaking of this, says: “If you sleep amidst the lots, the wings of the dove are laid over with silver, and the hinder parts of the back in the paleness of gold.” That means if we shall keep the eyes of the understanding from regarding the things of heaven and of earth—this the Psalmist calls sleeping in the midst—we shall be firm in the faith, here called dove, the wings of which are the truths laid over with silver, because in this life the faith puts these truths before us obscurely beneath a veil. This is the reason why the soul calls them silvered surface. But when faith shall have been consummated in the clear vision of God, then the substance of faith, the silver veil removed, will shine as gold.
4. As the faith gives and communicates to us God Himself, but hidden beneath the silver of faith, yet it reveals Him none the less. So if a man gives us a vessel made of gold, but covered with silver, he gives us in reality a vessel of gold, though the gold is covered over. Thus, when the bride in the Canticle was longing for the fruition of God, He promised it to her so far as the state of this life admitted of it, saying: “We will make you chains of gold inlaid with silver.” He thus promised to give Himself to her under the veil of faith. Hence the soul addresses the faith, saying: “Oh that on your silvered surface”—the definitions of faith—”in which you hide” the gold of the divine rays—which are the desired eyes,—instantly adding:
“You would mirror forth at once those desired eyes!”
5. By the eyes are understood, as I have said, the rays and truths of God, which are set before us hidden and informal in the definitions of the faith. Thus the words say in substance: “Oh that you would formally and explicitly reveal to me those hidden truths which You teach implicitly and obscurely in the definitions of the faith; according to my earnest desire.” Those truths are called eyes, because of the special presence of the Beloved, of which the soul is conscious, believing Him to be perpetually regarding it; and so it says:
“Which are outlined in my heart.”
6. The soul here says that these truths are outlined in the heart—that is, in the understanding and the will. It is through the understanding that these truths are infused into the soul by faith. They are said to be outlined because the knowledge of them is not perfect. As a sketch is not a perfect picture, so the knowledge that comes by faith is not a perfect understanding. The truths, therefore, infused into the soul by faith are as it were in outline, and when the clear vision shall be granted, then they will be as a perfect and finished picture, according to the words of the Apostle: “When that shall come which is perfect, that shall be made void which is in part.” “That which is perfect” is the clear vision, and “that which is in part” is the knowledge that comes by faith.
7. Besides this outline which comes by faith, there is another by love in the soul that loves—that is, in the will—in which the face of the Beloved is so deeply and vividly pictured, when the union of love occurs, that it may be truly said the Beloved lives in the loving soul, and the loving soul in the Beloved. Love produces such a resemblance by the transformation of those who love that one may be said to be the other, and both but one. The reason is, that in the union and transformation of love one gives himself up to the other as his possession, and each resigns, abandons, and exchanges himself for the other, and both become but one in the transformation wrought by love.
8. This is the meaning of St. Paul when he said, “I live, now, not I, but Christ lives in me.” In that He says, “I live, now, not I,” his meaning is, that though he lived, yet the life he lived was not his own, because he was transformed in Christ: that his life was divine rather than human; and for that reason, he said it was not he that lived, but Christ Who lived in him. We may therefore say, according to this likeness of transformation, that his life and the life of Christ were one by the union of love. This will be perfect in heaven in the divine life of all those who shall merit the beatific vision; for, transformed in God, they will live the life of God and not their own, since the life of God will be theirs. Then they will say in truth. “We live, but not we ourselves, for God lives in us.”
9. Now, this may take place in this life, as in the case of St. Paul, but not perfectly and completely, though the soul should attain to such a transformation of love as shall be spiritual marriage, which is the highest state it can reach in this life; because all this is but an outline of love compared with the perfect image of transformation in glory. Yet, when this outline of transformation is attained in this life, it is a grand blessing, because the Beloved is so greatly pleased therewith. He desires, therefore, that the bride should have Him thus delineated in her soul, and says to her, “Put Me as a seal upon your heart, as a seal upon your arm.” The heart here signifies the soul, wherein God in this life dwells as an impression of the seal of faith, and the arm is the resolute will, where He is as the impressed token of love.
10. Such is the state of the soul at that time. I speak but little of it, not willing to leave it altogether untouched, though no language can describe it.
11. The very substance of soul and body seems to be dried up by thirst after this living well of God, for the thirst resembles that of David when he cried out, “As the hart longs for the fountains of waters, so my soul longs for You, O God. My soul has thirsted after the strong living God; when shall I come and appear before the face of God?” So oppressive is this thirst to the soul, that it counts it as nothing to break through the camp of the Philistines, like the valiant men of David, to fill its pitcher with “water out of the cisterns of Bethlehem,” which is Christ. The trials of this world, the rage of the devil, and the pains of hell are nothing to pass through, in order to plunge into this fathomless fountain of love.
12. To this we may apply those words in the Canticle: “Love is strong as death, jealousy is hard as hell.” It is incredible how vehement are the longings and sufferings of the soul when it sees itself on the point of testing this good, and at the same time sees it withheld; for the nearer the object desired, the greater the pangs of its denial: “Before I eat,” says Job, “I sigh, and as it were overflowing waters so my roaring” and hunger for food. God is meant here by food; for in proportion to the soul’s longing for food, and its knowledge of God, is the pain it suffers now.
 Hos. 2:20
 John 4:14
 John 7:39
 Ps. 67:14
 Cant. 1:10
 1 Cor. 13:10
 Gal. 2:20
 Cant. 8:6
 Ps. 41:1,2
 1 Chr. 11:18
 Cant. 8:6
 Job 3:24