The Gospel According to Mark 9:17-31
At that time, a man came to Jesus kneeling and saying: "Teacher, I brought my son to you, for he has a dumb spirit; and wherever it seizes him it dashes him down; and he foams and grinds his teeth and becomes rigid; and I asked your disciples to cast it out, and they were not able." And he answered them, "O faithless generation, how long am I to be with you? How long am I to bear with you? Bring him to me." And they brought the boy to him; and when the spirit saw him, immediately it convulsed the boy, and he fell on the ground and rolled about, foaming at the mouth. And Jesus asked his father, "How long has he had this?" And he said, "From childhood. And it has often cast him into the fire and into the water, to destroy him; but if you can do anything, have pity on us and help us." And Jesus said to him, "If you can! All things are possible to him who believes." Immediately the father of the child cried out and said, "I believe; help my unbelief!" And when Jesus saw that a crowd came running together, he rebuked the unclean spirit, saying to it, "You dumb and deaf spirit, I command you, come out of him, and never enter him again." And after crying out and convulsing him terribly, it came out, and the boy was like a corpse; so that most of them said, "He is dead." But Jesus took him by the hand and lifted him up, and he arose. And when he had entered the house, his disciples asked him privately, "Why could we not cast it out?" And he said to them, "This kind cannot be driven out by anything but prayer and fasting." They went on from there and passed through Galilee. And he would not have any one know it; for he was teaching his disciples, saying to them, "The Son of man will be delivered into the hands of men, and they will kill him; and when he is killed, after three days he will rise."
On St. John: The memory of this Saint is celebrated on March 30, where his biography may be found. He is celebrated today because his book, The Ladder of Divine Ascent, is a sure guide to the ascetic life, written by a great man of prayer experienced in all forms of the monastic polity; it teaches the seeker after salvation how to lay a sound foundation for his struggles, how to detect and war against each of the passions, how to avoid the snares laid by the demons, and how to rise from the rudimental virtues to the heights of Godlike love and humility. It is held in such high esteem that it is universally read in its entirety in monasteries during the Great Fast.