23 And Jesus said to him, 'If thou art able to believe! all things are possible to the one that is believing;' 24 and immediately the father of the child, having cried out, with tears said, 'I believe, sir; be helping mine unbelief.' 25 Jesus having seen that a multitude doth run together, rebuked the unclean spirit, saying to it, 'Spirit—dumb and deaf—I charge thee, come forth out of him, and no more thou mayest enter into him;'
Matthew Henry's Commentary on Mark 9:23-25
Commentary on Mark 9:14-29
(Read Mark 9:14-29)
The father of the suffering youth reflected on the want of power in the disciples; but Christ will have him reckon the disappointment to the want of faith. Very much is promised to our believing. If thou canst believe, it is possible that thy hard heart may be softened, thy spiritual diseases may be cured; and, weak as thou art, thou mayest be able to hold out to the end. Those that complain of unbelief, must look up to Christ for grace to help them against it, and his grace will be sufficient for them. Whom Christ cures, he cures effectually. But Satan is unwilling to be driven from those that have been long his slaves, and, when he cannot deceive or destroy the sinner, he will cause him all the terror that he can. The disciples must not think to do their work always with the same ease; some services call for more than ordinary pains.