In A Spiritual Canticle of the Soul and the Bridegroom Christ, St. John states:
"I do not purpose here to set forth all that greatness and fullness the spirit of love, which is fruitful, embodies in it. Yes, rather it would be foolishness to think that the language of love and the mystical intelligence - and that is what these stanzas are - can be at all explained in words of any kind, for the Spirit of our Lord who helps our weakness."
John of the Cross was a major figure of the Counter-Reformation, a Spanish mystic, Catholic saint, Carmelite friar and priest. He is considered, along with Saint Teresa of Ávila, as a founder of the Discalced Carmelites. His poetry and his studies on the growth of the soul are considered the summit of mystical.