A common objection to St. Teresa’s mysticism is that it is too sexual. The erotic overtones of the passage describing St. Teresa’s transverberation and the sensuality of Bernini’s sculpture are rather obvious. This imagery can shock many pious Christians, especially Protestants, but also many Catholics who are (understandably) disquieted by a middle-aged nun who makes a mystical experience of God’s love sound like a sexual encounter with an angel.
I saw in his hand a long spear of gold, and at the iron's point there seemed to be a little fire. He appeared to me to be thrusting it at times into my heart, and to pierce my very entrails; when he drew it out, he seemed to draw them out also, and to leave me all on fire with a great love of God. The pain was so great, that it made me moan; and yet so surpassing was the sweetness of this excessive pain, that I could not wish to be rid of it. The soul is satisfied now with nothing less than God. The pain is not bodily, but spiritual; though the body has its share in it. It is a caressing of love so sweet which now takes place between the soul and God, that I pray God of His goodness to make him experience it who may think that I am lying.
—St. Teresa of Avila, Autobiography, chapter XXIX
St. Teresa’s use of sexual images to describe her experience, while shocking at first, is actually not blasphemous, when properly understood. Even today in a culture that is saturated with sex and largely agnostic about any kind of ultimate meaning, sex is apparently one thing that strikes most people as existentially important precisely because it points the way to transcendence. People still sense that sex can take them outside themselves—in a sort of ecstasy—and give them love, and perhaps even a foretaste of divine love. This desire to achieve transcendence in sex is reflected in G.K. Chesterton's aphorism, “Every man who knocks on the door of a brothel is looking for God.” Because sex possesses this awesome power to open man up to transcendence, to God's grace, it is the most apt point of comparison that St. Teresa (and other mystics) can use in trying to express the ineffable.
Another point of comparison that St. Teresa makes use of in her Autobiography, which might also strike the pious as overly sensual, is drunkenness. A number of times St. Teresa compares what she feels during her mystical experiences to being drunk. The similarities between a mystic trance and intoxication (whether from alcohol or drugs) are numerous: both can induce a kind of trance in which time seems to be suspended; both can result in visions; both states are hard to describe to someone who has not experienced them, etc. Because of these similarities, some Native Americans use peyote in their religious rituals, and the more idealistic hippies of the 1960’s (and even Ernst Jünger) used LSD as a way to induce mystical experiences.
Despite these superficial similarities, though, it is probably more accurate to say that alcohol and drugs mimic, rather than induce, mystical experiences because they represent the exaltation of technique over transcendence. Many people (at least those who seek more than mere physical pleasure) apparently think that the right mixture of chemicals or the right position in bed will endow their lives with new meaning. They think these techniques can work as a short-cut to transcendence. These techniques, however, will fail because all they do is produce a subjective feeling of transcendence, rather than objectively transform the person, making him more open to God's grace. St. Teresa emphasizes often—as opposed to Luther’s teachings on grace—that mystical experiences do us no good, and may actually come from the devil, if they do not objectively bring us closer to God. St. Teresa’s mysticism, then, follows the Church’s consistent teaching (as formulated by St. Thomas Aquinas): “Grace does not destroy nature, but perfects it.”
One of St. Teresa’s fundamental precepts (which she gives in a slightly different context) could be applied to alcohol and drugs: “People should not try to rise unless they are raised by God” (ch. XII). Indulging in sex and drugs is nothing like the hard work required in a life of prayer. St. Teresa frankly acknowledges that she spent decades struggling before ever really achieving prayer. She also warns her readers that they must be prepared to endure this aridity (sequedad) for their entire lives. According to St. Teresa, it is less difficult to suffer a quick martyrdom than it is to lead a life of contemplative prayer. In other words, openness to God's grace often requires enduring a certain agony while one waits to be raised by God.
Nevertheless, St. Teresa also assures her readers that prayer can have many rewards even in this life, and many readers, wary of a life of aridity, may latch onto these passages. Can all her talk of sex and alcohol, then, be taken too far or be understood in the wrong way? Of course it can. But, St. Teresa herself provides us with one of the key safeguards against this potential danger: she repeats throughout her Autobiography that anyone who is serious about prayer needs a wise spiritual director. It is a spiritual director's job to keep the individual grounded, away from the danger of subjective whims, and, most importantly, open to God's grace.