For many in the modern West, mysticism now means the same thing as mystification, referring to a twilight world of the irrational and paranormal. If there’s a mysticism section at your local bookstore, what you’ll find there is likely a farrago of New Age blather, texts on crystal handling and tarot-card reading, and yoga manuals that promise weight loss and a better sex life. The idea behind this commercial convention is that mysticism is all about esoteric knowledge.

In the preface to her famous book on mysticism, now a century old, Evelyn Underhill wrote that her own understanding of the word had nothing in common with the way it was generally used even then. Mysticism, she observed, had become an “excuse for every kind of occultism, for dilute transcendentalism, vapid symbolism, religious or aesthetic sentimentality, and bad metaphysics.” (And she had never stepped foot in a Barnes & Noble.) As the late French scholar Michel de Certeau showed in his book The Mystic Fable, this popular understanding of mysticism can be traced back to the second half of the seventeenth century. But for Christians, the term mysticism has another meaning.

It is generally recognized that St. John of the Cross (1542–91) was a mystic. What does that mean exactly? What did he understand mysticism to be? In fact, John might have been puzzled if someone had called him a mystic, if only because the terms “mystic” and “mysticism” were not yet in common usage when he lived. Yet St. John was familiar with the term “mystical theology,” which has a very long ancestry. In The Ascent of Mount Carmel, he writes, “Contemplation, by which the intellect has a higher knowledge of God, is called mystical theology, meaning the secret wisdom of God.” Elsewhere in his writings, John will use the adjective “mystical” to modify both “wisdom” and “knowledge.”

A closer look at the second part of the phrase “mystical theology” might help us understand the first. For John, the word “theology” referred not to an academic discipline but to the inner life of the holy Trinity, by which, in an eternal now, the Father utters the Word (Logos) and breathes forth that love we call the Spirit. The tradition that nourished St. John distinguished this inner life of the Trinity from the pouring forth of that life by way of revelation—first in creation, then in the life of the Chosen People, and finally in the Incarnation. The former is called “theology”; the latter, “economy.” In the first millennium, then, theology meant either the inner life of the Trinity or our participation in that life. In the words of Evagrius of Pontus, “Whoever prays is a theologian.”

The adjective “mystical” was used by the ancient Christian writers to describe a variety of things, but generally it simply meant “hidden.” Scripture had both a plain sense, which every literate person could understand, and a hidden, “mystical” one discovered only through the eyes of faith. The Eucharist, too, had both a plain sense (bread and wine) and a mystical one for those who received it in faith; for them, it was the body and blood of Christ. The same adjective was used for the church, which could be viewed either as a sociological reality or as the Mystical Body of Christ. The cognate word mystery was frequently a synonym for a sacrament because a sacrament had both a plain and a hidden meaning. Baptism involved both a visible pouring of water and an invisible regeneration.

Mystical theology, then, was the hidden outpouring of trinitarian love as Christians experience it. The term was coined around the year 500 AD by an unknown monastic writer who claimed to be the Dionysius converted by St. Paul in Athens (Acts 17:34). Pseudo-Dionysius’s short treatise The Mystical Theology, which is less than ten pages long in English translation, was a companion to another work known as The Divine Names. The two texts were meant to be read together dialectically. Pseudo-Dionysius understood that one can affirm many things of God, as testified by the many names ascribed to God in sacred Scripture. Yet none of those names is adequate to the profound reality to which they refer. God is not really a shepherd, and is only analogously a rock or a father. It’s worth noting that Pseudo-Dionysius begins his treatise on mystical theology with a prayer to the Trinity, for the trinitarian mystery is radically unknowable. Thus, mystical theology means the hidden discourse of God. The fourteenth-century author of The Cloud of Unknowing, who translated Pseudo-Dionysius’s text into Middle English, got it right when he called his translation “Denys’s hidden divinity.”

Pseudo-Dionysius wrote in Greek but his works were translated into Latin very early in the medieval period by the ninth-century Irish writer John Eruigena. Dionysius’s writings were venerated both for their profundity and for their supposed apostolic origins. He left his mark on every one of the great medieval doctors. St. Bonaventure cites Dionysius frequently; St. Thomas wrote commentaries on his work, as did Thomas’s teacher St. Albert the Great. It is through them that John of the Cross learned his mystical theology.

When John wrote about mystical theology, therefore, he was writing from within a tradition in which his subject was not a technical or theoretical discourse but an experience of the triune God’s incomprehensible love. John did not think of this experience as having anything to do with the extraordinary experiences now commonly associated with the “mystic”: locutions, raptures, etc. It is reported that John once said he wouldn’t walk across the city plaza to see a stigmatic. He thought such spectacular religious epiphenomena were a distraction from that readiness to receive the grace of prayer that is the Christian mystic’s first concern. Nor did he think we should seek to experience the love of God just because it felt good, since in that case we would really be seeking a feeling, not God.

Of course, as contemporary scholars like Denys Turner, Mark McIntosh, and Bernard McGinn have shown, the dark path of negation taught by St. John is not the only hidden path of prayer. The history of Christian mystical prayer has admitted many different approaches. Christian mystics have used various metaphors, mainly drawn from Scripture, to mark out the road to the experience of trinitarian love. Some invoke the Exodus journey, others the ascent of a mountain. Another favorite metaphor was the ladder, inspired by the dream of Jacob described in Genesis. Still others, borrowing from St. Paul, have talked about the Christian soul moving from spiritual childhood to spiritual maturity. There is also a long and honorable tradition going back to the third century that uses nuptial imagery drawn from the Song of Songs. Let us repeat: These are all metaphors, and only metaphors. But among them is a foundational insight: One must pass from the world of sin and disorder in order to see in a new way, and, finally, in order to be open to a deeper experience of God’s love. Behind that insight one finds the ancient path of purgation, illumination, and union—a path first outlined in the third century by Origen of Alexandria in the prologue to his commentary on the Song of Songs. It is hard to overestimate the influence this three-staged model of spiritual growth has had on the subsequent history of Christianity.

All the mystics in the Christian tradition assumed that the person of prayer who sought a deep intimacy with God would participate in the ordinary means of holiness in the church: regular prayer, participation in the sacraments, a sensible approach to asceticism, and the works of charity. In fact, St. Teresa of Ávila’s The Interior Castle had a very simple criterion for judging whether someone had had an experience of the hidden love of God: Did that person love her sisters more? In one of his informal talks to young friars, Meister Eckhart said that if a person were lifted by rapturous prayer into the third heaven described by St. Paul and knew that a brother was sick, it would be better to climb down and bring that ailing brother a bowl of soup. It is care for the ordinary duties of life that motivated Evelyn Underhill to insist that those who were under her spiritual direction do good works for the poor, lest they think that progress in contemplative prayer was for the sake of the self and its own joys. The Swiss theologian Hans Urs von Balthasar said that the first proof of genuine mystical consciousness was that a person showed a definite love for both God and neighbor. In short, the mystical experience is not to be construed as some sort of Plotinian flight of the alone with the Alone.

Contrary to the popular image of the mystic as a recluse, St. John of the Cross traveled (that is, walked!) about fifteen hundred miles during his active ministry. He taught; he organized; he built an aqueduct still in use today. Nor did most mystics live under a cloud of suspicion by church authority. While it’s true that Meister Eckhart had his problems with the papacy and Teresa of Ávila had a scrape or two with the Inquisitors in Spain, for the most part the mystics were regarded, even in their own lifetimes, as reformers and leaders of what would become “schools of spirituality.” But it’s hard to erase the persistent cliché of mystics as persecuted rebels. Many still wish to believe that mystics stood apart from the community of ordinary Christians rather than at its heart.

The German theologian Karl Rahner famously said that the Christian of the future would have to be a mystic. What he meant was that the traditional cultural support for religious observance was in a state of rapid erosion, so that, if a person didn’t have a deep personal experience of the reality of God’s love, there was little left to hold him or her to a conventional practice of the faith. Rahner believed that God’s self-communication was at the heart of human experience. For this reason, Harvey Egan, SJ, has called Rahner the “theologian of experienced grace.” It was of no concern to Rahner whether this experience was called “mystical” or not. The critical point was that the experience of grace—that is, the sense of God’s presence—was not something reserved for spiritual virtuosos, but open to all.

We can learn much from the two-thousand-year history of Christian spirituality about how to encounter God’s word fruitfully, how to pray according to this or that “method,” how to coordinate our various activities mindfully, and how to participate more fully in the liturgical and devotional practices of the church. Traditions of Christian spirituality shouldn’t be thought of as ossified models to be followed slavishly but rather as ongoing experiments from which we might glean useful lessons. All these methods, practices, and “ways” are means, not ends; and they are situated squarely within the church. Mystical consciousness is simply the full flowering of an ordinary Christian life, rooted in the creed and nourished by the sacraments.

If I understand the issue correctly, one does not set out to become a mystic as a golfer might set out to become a member of the PGA. The kind of experience described as contemplative or mystical comes as a gift to those ready to receive it rather than a reward for hard work or native talent.

So how do we become ready? One answer to that question is a deceptively simple imperative common in the early patristic tradition: Remember God. Those who remember God, by participating in the ordinary life of the church and acting justly and lovingly toward others, will come increasingly to sense the presence of God in their lives. Sometimes, however, they may also experience a sense of his absence, as their initial understanding of God begins to recede. John of the Cross wrote at length about this painful experience, assuring his readers that this “dark night” of the senses and of faith would be followed by a dawn. (The oft-cited distinction between John’s “dark” mysticism and a “mysticism of light” is too simple. After all, John of the Cross’s last work has in its very title a metaphor of light: The Living Flame of Love.)

For a number of years I have taught a course on prayer for undergraduates at the University of Notre Dame. I never ask my students to share their own experiences with me because I never want to be in the position of suggesting to a student that his or her prayer life is a C minus. Despite my caution, students do write about their own experiences in their papers, and some of them write so compellingly that I have sometimes felt unworthy to teach them. One could call some of these students mystics without abusing the term, and I suspect there are many such mystics in the church, people who do not stand out or inspire new movements but quietly bear witness to an experience of—and not just a belief in—God.

Perhaps we ought to quit using the terms “mystic” and “mysticism,” because they have become so disfigured. But if it’s too late to retire these terms (and it probably is), we can at least try to be more careful about how we use them. The mystic is not some Baroque figure who, having floated around in the sky with Bach playing in the background amid the flutter of angels, descends to earth in order to dictate his or her experience to a waiting secretary. The mystic is that Every Person who has learned the truth of the psalmist who urges us to “be still and know that I am God.” To learn that truth requires not strenuous effort but simple humility and perseverance. Whenever we sense the real presence of God in our hearts, whenever we are made to feel that, as St. Augustine put it, God is closer to us than we are to ourselves, then we are on the threshold of true Christian mysticism.

Art: The Holy Trinity with Augustine and the Blessed George of Cremona, Andrea Prevital, 1517

Related: Masked Mysticism, by Jerry Ryan