The prayer of faith
And Jesus answering saith unto them, Have faith in God. For verily I say unto you, That whosoever shall say unto this mountain, Be thou removed, and be thou cast into the sea; and shall not doubt in his heart, but shall believe that those things which he saith shall come to pass; he shall have whatsoever he saith. Therefore I say unto you, What things soever ye desire, when ye pray, believe that ye receive them, and ye shall have them. Mark 11:22-24
Certain faith-healers may claim that if you just have enough faith, then you can get whatever you pray for. We know this is false. Our Lord himself prayed that the cup of crucifixion might pass from him, and his Father said, no. Our salvation hinges upon that no! (And we must not think that Jesus didn't get it because of unbelief!). The apostle Paul prayed three times for God to remove some sort of physical infirmity (the thorn in the flesh), and God also said no all three times. Paul learned something precious from that, namely, that God's strength is made perfect in our weakness.
So we must not give in to the charade that is faith-healing and the word of faith movement. It is a blasphemous heresy. And yet we must also be careful that we do not go over into the opposite ditch. Our Lord clearly says in the verses above that faith can move mountains and that, on the other hand, doubt cripples our spiritual effectiveness. There is truth in the fact that the extent to which we are willing to trust in God's power and wisdom for our lives, to such an extent can we expect God's blessing upon our lives. Our Lord could not do many mighty miracles in Galilee, not because he couldn't but because he wouldn't - God will not honor unbelief with his blessing (Mk. 6:5).
There are limits to this principle, of course, and we must not put God in a box or limit his own sovereignty. Thank God he comes to his elect and gives them faith when they had none and puts them into his family (Jn. 1:12-13). But the principle still holds. God honors the life of faith. He blesses those who put their trust in him.
We have every reason to do so. For we not only have dried up fig trees as evidence, but an empty tomb. We have the logic of the cross: "He that spared not his own Son, how shall he not with also freely give us all things?" (Rom. 8:32). What greater reason do we have to rest ourselves, whole and entire, upon the God of grace and glory?