It must be known, then, that the soul, after it has been definitely converted to the service of God, is, as a rule, spiritually nurtured and caressed by God, even as is the tender child by its loving mother, who warms it with the heat of her bosom and nurtures it with sweet milk and soft and pleasant food, and carries it and caresses it in her arms; but, as the child grows bigger, the mother gradually ceases caressing it, and, hiding her tender love, puts bitter aloes upon her sweet breast, sets down the child from her arms and makes it walk upon its feet, so that it may lose the habits of a child and betake itself to more important and substantial occupations. The loving mother is like the grace of God, for, as soon as the soul is regenerated by its new warmth and fervour for the service of God, He treats it in the same way; He makes it to find spiritual milk, sweet and delectable, in all the things of God, without any labour of its own, and also great pleasure in spiritual exercises, for here God is giving to it the breast of His tender love, even as to a tender child.
-John of the Cross, The Dark Night of the Soul
John of the Cross (1542 – 1591 AD), born Juan de Yepes Álvarez, was a major figure of the Counter-Reformation and contributed much to the mystical tradition. Known especially for his writings, both his poetry and his studies on the growth of the soul are considered one of the peaks of all Spanish literature. He was canonized as a saint in 1726 by Pope Benedict XIII and is one of the thirty-three Doctors of the Church.