“There are psycho-physical techniques that can help this effort towards harmonization – yoga, for example. None the less, I would discourage you from putting too great an emphasis on yoga techniques (as with true Hatha yoga). First, because these techniques depend on the supervision of an experienced master and the context of a living tradition; otherwise they risk being hurtful, even to health. Secondly, because these techniques are conceived in the light of an understanding of the human person and a spiritual ideal that are different from those of Christianity. Their goal is an interiority closed in on itself, an en-stasis, whereas Christianity is a religion of love that results in an open interiority, an ex-stasis. This is to speak too simplistically of a great tradition, but it is enough to help us realize that the fundamental orientation is different.
At the same time, it seems to me that we can derive great benefit from certain elementary techniques, the type of yoga used to master, stretch and calm the psycho-spiritual organism. What seems to me chiefly necessary in our time for many young people is a certain training in psycho-physical stillness and in the mental concentration so necessary for the life of prayer. It is very humble work, if you like, that seeks to facilitate from a distance, both the active and passive aspects of the theological virtues, faith, hope, and charity.”
pg. 117, The Way of Silent Love, by a Carthusian