What a commentary on such words this story affords! What has become of the disciples' supernatural might? Has it ebbed away as suddenly as it flowed? Is their Lord's endowment a shadow or His assurances delusion? Has He taken back what He gave? Not so. And yet His servants are ignominiously beaten. One poor devil-ridden boy brings all their resources to nothing. He stands before them writhing in the gripe of his tormentor, but they cannot set him free. The importunity of the father's prayers is vain, and the tension of expectancy in his eager face relaxes into the old hopeless languor as he slowly droops to the conviction that 'they could not cast him out.' The malicious scorn in the eyes of the Scribes, those hostile critics who 'knew that it would be so,' helps to produce the failure which they anticipated. The curious crowd buzz about them, and in the midst of it all stand the little knot of baffled disciples, possessors of power which seems to leave them when they need it most, with the unavailing spells dying half spoken on their lips, and their faint hearts longing that their Master would come down from the mount, and cover their weakness with His own great strength. No wonder that, as soon as Christ and they are alone, they wish to know how their mortifying defeat has come about. And they get an answer which they little expected, for the last place where men look for the explanation of their failures is within; but they will ascend into the heavens, and descend into the deeps for remote and recondite reasons, before they listen to the voice which says, 'The fault is nigh thee, in thy heart.' Christ's reply distinctly implies that the cause of their impotence lay wholly in themselves, not in any defect or withdrawal of power, but solely in that in them which grasped the power. They little expected, too, to be told that they had failed because they had not been sure they would succeed. They had thought that they believed in their ability to cast out the demon. They had tried to do so, with some kind of anticipation that they could. They had been surprised when they found that they could not. They had wonderingly asked why. And now Christ tells them that all along they had had no real faith in Him and in the reality of His gift. So subtly may unbelief steal into the heart, even while we fancy that we are working in faith. And a further portion of our Lord's reply points them to the great means by which this conquering faith can be maintained--namely, prayer and fasting. If, then, we put all these things together, we get a series of considerations, very simple and commonplace indeed, but all the better and truer therefor, which I venture to submit to you, as having a very important bearing on all our Christian work, and especially on the missionary work of the Church. The principles which the text suggests touch the perpetual possession of the power which conquers; the condition of its victorious exercise by us, as being our faith;