In 1959 Martyn Lloyd-Jones gave a series of messages on revival. One of these expositions was on Mark 9, where Jesus comes off the mountain of transfiguration and discovers his disciples trying unsuccessfully to exorcise a demon from a boy. After he rids the youth of the demonic presence, the disciples ask him, “Why could we not cast it out?” Jesus answers, “This kind cannot be driven out by anything but prayer” (Mark 9:28-29). Jesus was teaching his disciples that their ordinary methods did not work for “this kind.” Lloyd-Jones went on to apply this to the church:
“Here, in this boy, I see the modern world, and the disciples I see the Church of God…I see a very great difference between today and two hundred years ago, or indeed even one hundred years ago. The difficulty in those earlier times was that men and women were in a state of apathy. They were more or less asleep…There was no general denial of Christian truth. It was just that people did not trouble to practise it…All you had to do then was to awaken them to rouse them…
But the question is whether that is still the position…What is ‘this kind’?…The kind of problem facing us is altogether deeper ad more desperate…The very belief in God has virtually gone…The average man today believes that all this belief about God and religion and salvation…is an incubus on human nature all through the centuries…
It is no longer merely a question of immorality. This has become an amoral or a non-moral society. The very category of morality is not recognized…
The power that the disciples had was a good power, and it was able to do good work in casting out the feeble devils, but it was no value in the case of that boy (D. Martyn Lloyd-Jones, Revival (Wheaton, IL: Crossway Books, 1987, pp. 9, 13-15).
Put simply, Jesus is saying, the demon is in too deep for your ordinary way of doing ministry.
(Excerpt From Timothy Keller The Gospel and the Supremacy of Christ)