Without trying to make of the Christian life a cult of suffering for its own sake, we must frankly admit that self-denial and sacrifice are absolutely essential to the life of prayer.
If the life of prayer is to transform our spirit and make us "new men" in Christ, then prayer must be accompanied by "conversion," metanoia, that deep change of heart in which we die on a certain level of our being in order to find ourselves alive and free on another, more spiritual level. . . .
Thomas Merton, The Climate of Monastic Prayer