The feast day in the EF of St. John of the Cross is November 24th. The Low Mass I attended was attended by about 30 people, the regulars, as one said. There were about six young people in their twenties there, excluding the altar server. This is good news.
St. John of the Cross is the great Doctor of the Church who teaches us about mysticism. I highly recommend reading his work but only with the approval or aid of a spiritual director. His experiences were what is called Extraordinary Contemplation, the experience of great mystics. St. Teresa of Avila, of course, is the other Doctor of the Church who explains this type of contemplation.
Mystical experiences are sheer gift, occurring without any effort on our part. This is a great difference between Ordinary Contemplation and Extraordinary Contemplation. Of course, all prayer is gift, but the first type is something to which we can aspire in prayer. Whether all people can and are willed by God to experience Extraordinary Contemplation is open to discussion. The state is seen by some as willed by God for all people. Garrigou-Lagrange would fall into the category of theologians who believe that God is calling all to the unitive state.
The reason one should read these books with the approval of a spiritual director is to avoid deceit in one's life. I shall post more on this again.
Here is St. Teresa of Avila's definitions, from her Life, taken from the Catholic Encyclopedeia. Also, the fruits of the prayer of quiet follow. May I note that only those who are in sanctifying grace and in complete orthodoxy with the Catholic Church can rise to this level of prayer. Many heretics may have gotten to the illuminative stage and lost grace through pride, but none would be able to experience union.
- incomplete mystical union, or the prayer of quiet (from the Latin quies, quiet; which expresses the impression experienced in this state);
- the full, or semi-ecstatic, union, which St. Teresa sometimes calls the prayer of union (in her "Life" she also makes use of the termentire union, entera unión, ch. xvii);
- ecstatic union, or ecstasy; and
- transforming or deifying union, or spiritual marriage (properly) of the soul with God.
- interior peace which remains after the time of prayer,
- profound humility,
- aptitude and a disposition for spiritual duties,
- a heavenly light in the intellect, and
- stability of the will in goodness.