Christian mysticism is rooted in the mystery of Christ, and the only secret knowledge it provides is the knowledge of faith. Faith's secret is the secret of love. The Bride of Christ lives in the presence of her Beloved from whom she receives the secret of love. All who share this secret discover a whole new way of life, a supernatural kind of living in this world but not of it. This is true mystical knowledge, a kind of knowing that results from the members of Christ body encountering Christ Himself.
This ‘hidden’ knowledge should not be confused with esoteric experiences which some non-Christian spiritualities claim to provide. Esoteric knowledge or enlightenment is arrived at by meditation technique and is at best an admirable human achievement. Christian mysticism does not culminate in this sort of enlightenment nor is it the result of what is mastered by techniques. The knowledge which Christian faith provides is “mystical” insofar as it involves a union with the mystery of Christ through the holy mysteries unto union with the Holy Trinity. It is a contemplative knowledge that anticipates the ultimate end of the Divine Economy, the perfect unity of creatures with the Holy Trinity in which the fulfillment of all desire is realized – that eternal beatific vision of inexhaustible and exceeding Love.
In itself, such knowledge is beyond the ability of human speech to fully communicate because it exceeds the power of human intelligence to conceptualize. The mystery of Christ cannot be contained in the narrow confines of any created intelligence’s categories of thought. This kind of knowledge is so different from natural knowledge that some comtemplatives refer to it as "unknowing." All other thought loses its dynamism, except the thought of Christ. The only reason this kind of mystical knowing is possible is because in the fullness of time, the Word became flesh.
Because the Word dwelt among us and poured out his substance on the Cross, the truth bearing statements of our faith, the articles of our faith, bear the Truth which is the Lord. It is this Truth that is encountered in Christian prayer and to which our faith holds fast. Because the natural power of the human mind is incapable of attaining it, it is described as a dark night, a cloud of unknowing, a wound and a ray of darkness. Because it surpasses all intellectual operations this knowledge is described as a loving glance, a touch and a divine kiss which goes beyond the intellect into the very substance of the soul. The mind receives this heart to heart by way of gift – the gift of faith. Under the fruitful power of the Holy Spirit, this gift opens up a purified understanding of divine things and the very wisdom of God. This kind of seeing which faith avails is called contemplation, a seeing which is at the same time a hearing of the Word.
Though the simplest of children can enjoy this loving knowledge, theologians and mystics struggle to articulate it. Yet, as St. Augustine observes, woe to us if we do not try because “No one can know the true meaning of the language of the spiritual writers if he is unable to explain it theologically; and, on the other hand, no one can know the sublimity of theology if he is ignorant of its relation to mysticism.” Garrigou-Lagrange, Three Ages of the Spiritual Life, trans. Sr. Timothea Doyle, OP, London: Herder (1948) pp 16 and 20.
Although theologians and mystics struggle to articulate this experience of the Church, anyone who has tasted such loving knowledge can no longer live as he once did. The merest of children experience this. Perhaps this is why Christianity is not the religion of aged gurus on top of mountains, but the faith of the children of God. When one meets the Lord in prayer, one finds oneself pierced to the heart, preoccupied with the magnitude of the friendship love of God revealed in Christ Jesus. Even if such a person were to fall back into his former way of life, he would have to contend with something profoundly unsettling and painfully haunting: namely, the indescribable joy discovered in meeting the Lord, and the unrequited sorrow of having turned away from him. (Think of the rich young man.)
To know Jesus Christ is not reducible to an intellectual experience – it is an experience that takes up one’s whole person and demands the response of one’s whole life. This kind of knowledge is transformative, making one’s life so completely different that some, like St. Paul, will “count all else as rubbish” save for this knowledge of Christ Jesus. Such knowledge demands a new way of life – a life in and for love alone. It is a performative knowledge. It leads to a life of fruitfulness, a life rooted in Christ’s salvific mission. But here I must end this already too long post!