Morning Bible Study: Jesus' Teaching on Prayer, Matthew 21:21-22

Matthew 21:21 Jesus answered them, “Truly I tell you, if you have faith and do not doubt, you will not only do what was done to the fig tree, but even if you tell this mountain, ‘Be lifted up and thrown into the sea,’ it will be done. 

22 And if you believe, you will receive whatever you ask for in prayer.”

Commentary
(the following is from Matthew Henry's Concise Commentary, 1706 -- www.christianity.com)

"[1.] The description of this wonder-working faith; If ye have faith, and doubt not. Note, Doubting of the power and promise of God is the great thing that spoils the efficacy and success of faith. "If you have faith, and dispute not" (so some read it), "dispute not with yourselves, dispute not with the promise of God; if you stagger not at the promise" (Rom. 4:20); for, as far as we do so, our faith is deficient; as certain as the promise is, so confident our faith should be.

[2.] The power and prevalence of it expressed figuratively; If ye shall say to this mountain, meaning the mount of Olives, Be thou removed, it shall be done. There might be a particular reason for his saying so of this mountain, for there was a prophecy, that the mount of Olives, which is before Jerusalem, should cleave in the midst, and then remove, Zec. 14:4. Whatever was the intent of that word, the same must be the expectation of faith, how impossible soever it might appear to sense. But this is a proverbial expression; intimating that we are to believe that nothing is impossible with God, and therefore that what he has promised shall certainly be performed, though to us it seem impossible. It was among the Jews a usual commendation of their learned Rabbin, that they were removers of mountains, that is, could solve the greatest difficulties; now this may be done by faith acted on the word of God, which will bring great and strange things to pass.

[3.] The way and means of exercising this faith, and of doing that which is to be done by it; All things whatsoever ye shall ask in prayer, believing, ye shall receive. Faith is the soul, prayer is the body; both together make a complete man for any service. Faith, if it be right, will excite prayer; and prayer is not right, if it do not spring from faith. This is the condition of our receiving—we must ask in prayer, believing. The requests of prayer shall not be denied; the expectations of faith shall not be frustrated. We have many promises to this purport from the mouth of our Lord Jesus, and all to encourage faith, the principal grace, and prayer, the principal duty, of a Christian. It is but ask and have, believe and receive; and what would we more? Observe, How comprehensive the promise is—all things whatsoever ye shall ask; this is like all and every the premises in a conveyance. All things, in general; whatsoever,brings it to particulars; though generals include particulars, yet such is the folly of our unbelief, that, though we think we assent to promises in the general, yet we fly off when it comes to particulars, and therefore, that we might have strong consolation, it is thus copiously expressed, All things whatsoever."