20 And in the morning, as they passed by, they saw the fig tree dried up from the roots. 21 And Peter calling to remembrance saith unto him, Master, behold, the fig tree which thou cursedst is withered away. 22 And Jesus answering saith unto them, Have faith in God. 23 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. 24 Therefore I say unto you, What things soever ye desire, when ye pray, believe that ye receive them, and ye shall have them. (Mark 11:20-24 KJV)
William Burkitt’s Commentary
The blasting and sudden withering of the fig tree at the word of Christ, plainly showed his divine power, and by this miraculous operation, our Saviour designed to show his disciples the mighty power of faith; that is, a full persuasion of the power of God, that he is able, and of the goodness of God, that he is willing, to grant whatever we ask according to his will, that has a tendency to his glory and our good.
Learn hence, That faith is a necessary and principal ingredient in prayer praying without faith, is like to a man’s shooting without a bullet; it makes a noise, but doth no execution.
Secondly, That whatsoever good thing God had made the matter of his promise, shall be given to good men in a way of performance, provided they pray in faith. Whatsoever ye desire, believe that ye receive them, and ye shall have them.