"This kind can come out by nothing, but prayer and fasting" (St. Mark 9:29).
This is the saving prescription of the greatest Physician of human souls. This is the remedy tried and proved. Another remedy for lunacy, there is not. What kind of sickness is that? That is the presence and dominance of an evil spirit in a man, a dangerous evil spirit who labors to eventually destroy the body and soul of man. The boy whom our Lord freed from an evil spirit; this evil spirit that had hurled him at times in the fire, at times in the water just in order to destroy him.
As long as a man only philosophizes about God he is weak and completely helpless against the evil spirit. The evil spirit ridicules the feeble sophistry of the world. But, as soon as a man begins to fast and to pray to God, the evil spirit becomes filled with indescribable fear. In no way can the evil spirit tolerate the aroma of prayer and fasting. The sweet-smelling aroma chokes him and weakens him to utter exhaustion. In a man who only philosophizes about faith, there is spacious room in him for the demons. But in a man who sincerely begins to pray to God and to fast with patience and hope, for the demon it becomes narrow and constricted and he must flee from such a man. Against certain bodily ills there exists only one remedy. Against the greatest ill of the soul, demonism, there exists two remedies, which must be utilized at one and the same time: fasting and prayer. The apostles and saints fasted and prayed to God. That is why they were so powerful against evil spirits.
O gracious Jesus, our Physician and Helper in all miseries, strengthen us by the power of Your Holy Spirit that we may be able to adhere to Your saving precepts concerning fasting and prayer for the sake of our salvation and the salvation of our fellow men.
To You be glory and thanks always. Amen.