Saint John of the Cross

"Would that men might come at last to see that it is quite impossible to reach the thicket of the riches and wisdom of God except by first entering the thicket of much suffering, in such a way that the soul finds there its consolation and desire. The soul that longs for divine wisdom chooses first, and in truth, to enter the thicket of the cross. [...]

The gate that gives entry into these riches of his wisdom is the cross; because it is a narrow gate, while many seek the joys that can be gained through it, it is given to few to desire to pass through it."  -- From a spiritual Canticle by Saint John of the Cross; Liturgy of the Hours, vol. I, Office of Readings, 1246-7.