Herein, spiritually, they become enemies of the Cross of Christ; for true spirituality seeks for God's sake that which is distasteful rather than that which is delectable; and inclines itself rather to suffering than to consolation; and desires to go without all blessings for God's sake rather than to possess them; and to endure aridities and afflictions rather than to enjoy sweet communications, knowing that this is to follow Christ and to deny oneself, and that the other is perchance to seek oneself in God, which is clean contrary to love.
For to seek oneself in God is to seek the favours and refreshments of God; but to seek God in oneself is not only to desire to be without both of these for God's sake, but to be disposed to choose, for Christ's sake, all that is most distasteful, whether in relation to God or to the world; and this is love of God.
(John of the Cross, Ascent of Mount Carmel, Book 2, Chapter 7, Paragraph 5)