"The life of prayer calls for continuous battles. It is the most important and the longest effort in a life dedicated to God. This effort has been given a beautiful name: it is called the guard of the heart. The human heart is a city; it was meant to be a stronghold. Sin surrendered it. Henceforth it is an open city, the walls of which have to be built up again. The enemy never ceases to do all he can to prevent this. He does this with his accustomed cleverness and strength, with stratagem and fury . . . he succeeds all along the line to distract us and entice us away from the divine presence. We must always be starting again. These continual recoveries, this endless beginning again, tires and disheartens us far more than the actual fighting. We would much prefer a real battle, fierce and decisive. But God, as a rule, thinks otherwise. He would rather we were in a constant state of war."
— Dom Augustin Guillerand, The Prayer of the Presence of God, p. 57