John of the Cross wrote some of his most luminous lines in the darkest of places. In the prison cell of Toledo in 1578, he composed the brief but profound poem La Fonte: ‘I know the stream proceeding from these two, that neither of them in fact precedes it, although it is night.’[1] These words, born in suffering, have been described as the creed of the mystic. In symbolic language, John expresses the foundations of all he believes: the Trinity, the mystery of divine life, and the soul’s participation in that life through faith. It is a celebration of ‘knowing,’ ‘believing,’ and ‘living in the darkness of faith.’
This article explores one central thread running through John’s writings: the Holy Spirit. If we take seriously the lines of La Fonte, we can say that John’s entire life is a life lived knowing the Holy Spirit, believing in the presence and action of the Holy Spirit, and living all of this in the darkness of faith. For John, everything we believe is lived in darkness — not confusion, but the luminous obscurity of faith. And this is true of the Holy Spirit also. The Spirit is known not by sight, not by feeling, but by the deep interior transformation that faith alone perceives.
Mary: The Model of Life in the Spirit
John’s model for this life of total docility to the Spirit is no one less than the Virgin Mary, Mother of Jesus. He writes:
Such was the prayer and work of our Lady, the most glorious Virgin. Raised from the beginning to this high state, she never had the form of any creature impressed in her soul, nor was she moved by any, for she was always moved by the Holy Spirit.[2]
This sentence is the foundation of John’s great devotion to Mary. She is the perfect disciple of her Son and the model for all disciples. To be ‘always moved by the Holy Spirit,’ free of all other attachments or influences, is the point of arrival of all John’s teaching. It is the ideal he sets before us. And in order to live the spiritual life well, we must keep this ideal before our eyes.
John’s teaching shows us that it is possible — indeed, this is the purpose for which we were created — to live life ‘always moved by the Holy Spirit.’ Mary reveals what humanity looks like when it is fully transparent to the Spirit’s action. She is not merely an example; she is the living embodiment of John’s vision of sanctification.
The Starting Point: The Trinity
To understand John’s teaching on the Holy Spirit, we must begin where he begins: with God. In another of his prison poems, the Romances on the Incarnation, John offers a vision of the Trinity that serves as a prologue to all his writings:
And thus, the glory of the Son was the Father’s glory, and the Father possessed all his glory in the Son. As the lover in the beloved each lived in the other, and the love that unites them is one with them, their equal, excellent as the One and the Other: Three Persons, and one Beloved among all three.[3]
He continues:
One love in them all makes of them one lover, and the Lover is the Beloved in whom each one lives. For the being that the three possess, each of them possesses, and each of them loves him who bears this being.[4]
And again:
Each one is this being, which alone unites them, binding them deeply, one beyond words. Thus, it is a boundless Love that unites them, for the three have one love which is their essence; and the more love is one the more it is love.[5]
One of John’s early commentators, Alonso de la Madre de Dios (1627), described this poem as a prologue to all John’s writings. Just as the Evangelist John begins his Gospel with a prologue that reveals the ‘big picture,’ so John of the Cross begins his teaching with a vision of the Trinity. We need this vision before we can understand the details of the spiritual life. We need to know who God is.
The book of Genesis tells us that we are made in the image and likeness of God (Genesis 1:27). John echoes this: ‘He created her in his image and likeness that she might attain such resemblance.’ In the Romances, John celebrates what we are created to resemble — nothing less than God’s very self, the Trinity. Therefore, to grow and mature humanly and spiritually, we must have a right understanding of who God is.
John’s Understanding of the Holy Spirit: A Single Movement with Four Currents
John’s teaching on the Holy Spirit unfolds as a single, continuous movement with four distinct currents, each flowing into the next and forming one coherent vision of divine life and human transformation.
First, the Holy Spirit is the eternal Love of the Father and the Son — the boundless, unifying Love celebrated in the Romances, the Love that is ‘their equal’ and ‘the Love that unites them.’ This is the Spirit’s identity: the divine Love who is God’s own inner life.
Second, this same Spirit is the interior transformer of the soul, the ‘flame of love’ that burns, consumes, and divinises, as John describes in the Living Flame: a fire that not only purifies but ‘refreshes the soul with a quality of divine life.’ The Spirit is not merely the Love within God; the Spirit is the Love poured into the soul.
Third, the Spirit is the guide of the spiritual journey, the one who moves the soul in the darkness of faith, and Mary is the living embodiment of this truth — the disciple who ‘was always moved by the Holy Spirit,’ revealing what full docility looks like. The Spirit leads the soul not by visions or feelings but by faith.
Finally, the Holy Spirit is the principal agent of sanctification, the one who performs the work of transformation from within, which is why John warns that spiritual directors must understand ‘the ways and properties of the Spirit,’ lest they hinder the very work God is doing. These four currents — the Spirit as Love, as Flame, as Guide, and as Sanctifier — form the living architecture of John’s understanding of the Holy Spirit.
The Flame That Lives: The Spirit’s Action in the Soul
If the Romances reveal who the Spirit is, the Living Flame of Love reveals what the Spirit does. This book is John’s most explicit teaching on the presence and action of the Holy Spirit. He writes:
This flame of love is the Spirit of the Bridegroom, who is the Holy Spirit. The soul feels him within itself not only as a fire that has consumed and transformed it but as a fire that burns and flares within it. And that flame, every time it flares up, bathes the soul in glory, and refreshes it with a quality of divine life.[6]
Here John describes the Spirit not as an idea, nor as a distant theological concept, but as a living flame within the soul. The Spirit consumes, transforms, burns, and refreshes. The Spirit is experienced as an interior fire that gives the soul a ‘quality of divine life.’ This is John’s language for divinisation — the soul becoming God-like by participation.
In the Living Flame, John shows that all the work of spiritual growth — the growth of the whole person — is the work of the Holy Spirit. Transformation and sanctification are the Spirit’s work. He writes:
The soul, then, should advert that God is the principal agent in this matter […] many spiritual masters cause great harm to a number of souls; not understanding the ways and properties of the Spirit.[7]
John is painfully aware of the tragic consequences of misunderstanding the Spirit. This is the motive for all his writings: ‘because it is extremely necessary to so many souls.’[8] He writes not to offer theories, but to protect souls from harm and to guide them into the true action of the Spirit.
The Darkness of Faith: The Spirit’s Environment
John insists that the Spirit’s work takes place in the ‘darkness of faith.’ This darkness is not the absence of God but the mode in which God is known. The Spirit does not act through visions, feelings, or extraordinary experiences. The Spirit acts in the quiet depths of faith, where the soul is stripped of all attachments and becomes free for God.
This is why Mary is so important for John. She is the one who ‘never had the form of any creature impressed in her soul.’ She lived entirely in faith, moved only by the Spirit. She reveals that the Spirit’s action is subtle, interior, and transformative. It is not dramatic; it is divine.
Conclusion: Living Always Moved by the Holy Spirit
John of the Cross offers the Church a profound and coherent teaching on the Holy Spirit. The Spirit is the eternal Love of Father and Son, the interior flame that transforms the soul, the guide of the spiritual journey, and the principal agent of sanctification. Mary reveals what it looks like to live entirely under the Spirit’s movement. The Romances reveal who the Spirit is. The Living Flame reveals what the Spirit does. And La Fuente reveals the environment in which the Spirit acts: the darkness of faith.
To live the Christian life, for John, is to allow the Holy Spirit — divine Love — to shape us, move us, and transform us into the likeness of Christ. It is to live, like Mary, ‘always moved by the Holy Spirit.’ It is to let the flame burn within us until we become flame ourselves.
This is the life John lived. This is the life he teaches. And this is the life offered to every disciple who dares to walk in the darkness of faith, trusting the Spirit who is Love.
[1] All citations from St John of the Cross are taken from The Collected Works of St John of the Cross, trans. Kieran Kavanaugh and Otilio Rodriguez (Washington, DC: ICS Publications, 2017). For La Fonte, see Poem No. 8 in the Poems section, pp. 58–60; the quoted lines are from stanza 8, which appears on p. 59.
[2] The Ascent of Mount Carmel, Book 3, chap. 2:10, p. 271
[3] Stanza 1 of Romances, p. 60-61.
[4] Ibid.
[5] Ibid.
[6] The Living Flame of Love, 1:3, p. 641.
[7] The Living Flame of Love, 3: 29, 31, pp. 684-685
[8] The Ascent of Mount Carmel, Prologue: 3, p.115
