“Christian life is a retreat. We are ‘not of this world’, just as Jesus Christ is ‘not of this world’ (John 17:14). What is the world? It is, as St. John said, the ‘lust of the flesh’, that is, sensuality and corruption in our desires and deeds; ‘the lust of the eyes’, curiosity, avarice, illusion, fascination, error, and folly in the affectation of learning, and, finally, pride and ambition (1 John 2:16). To these evils of which the world is full, and which make up its substance, a retreat must be set in opposition. We need to make ourselves into a desert by a holy detachment. Christian life is a battle … We must never cease to fight. In this battle, St. Paul teaches us to make an eternal abstinence, that is, to cut ourselves off from the pleasures of the senses and guard our hearts from them … it was to repair and to expiate the failings of our retreat, of our battle against temptations, of our abstinence, that Jesus was driven into the desert. His fast of forty days prefigured the lifelong one that we are to practice by abstaining from evil deeds and by containing our desires within the limits laid down by the law of God.”
—Bishop Jacques-Benigne Bossuet