Charles Spurgeon Commentary Matthew 17:21

"[But this kind goeth not out save by prayer and fasting.]" — Matthew 17:21 (ASV)

Although lack of faith was the chief hindrance to the healing of the afflicted child, the case was one in which special means were needed. Faith would have suggested and supplied these special means. Since they were absolutely necessary for the disciples to succeed in it, faith would have actively engaged with them.

With God all things are equally possible, but to us, one devil may be harder to deal with than another. One kind will go at a word, but of others it may be said, This kind goeth not out but by prayer and fasting.

The one who would overcome the devil in certain instances must first overcome heaven by prayer and conquer himself by self-denial. The "drink-devil" is one of this kind, which may assuredly be conquered by faith; yet we must generally use much intercession toward God and total abstinence, as an example toward others, before we can displace this demon.

Our business in the world is to deliver people from the power of the devil, and we must go to Jesus to learn the way. No amount of prayer or self-denial must be spared if we can thereby deliver one soul from the power of evil, and true faith in God will enable us to offer the prayer and practice the self-denial.

It may be that some of us have failed because we are not yet well instructed in the right method of procedure.

Either we are trying faith without using the appointed means, or we are using the means but not exercising simple faith in God; in either case, we will fail. If we go to work by faith in God, in Christ’s own way, we will drive out the evil spirit.