1 The Lord, by His promise, gave those whose hopes were resting on Himself a special ground of confidence, when He said, “For I go to the Father; and whatsoever you shall ask in my name, I will do it.” His proceeding, therefore, to the Father, was not with any view of abandoning the needy, but of hearing and answering their petitions. But what is to be made of the words, “Whatsoever you shall ask,” when we behold His faithful ones so often asking and not receiving? Is it, shall we say, for no other reason but that they ask amiss? For the Apostle James made this a ground of reproach when he said, “You ask and receive not, because ye ask amiss, that you may consume it upon your lusts.” What one, therefore, wishes to receive, in order to turn to an improper use, God in His mercy rather refuses to bestow. Nay, more, if a man asks what would, if answered, only tend to his injury, there is surely greater cause to fear, lest what God could not withhold with kindness, He should give in His anger. Do we not see how the Israelites got to their own hurt what their guilty lusting craved? For while it was raining manna on them from heaven, they desired to have flesh to eat. They disdained what they had, and shamelessly sought what they had not: as if it were not better for them to have asked not to have their unbecoming desires gratified with the food that was wanting, but to have their own dislike removed, and be made themselves to receive aright the food that was provided. For when evil becomes our delight, and what is good the reverse, we ought to be entreating God rather to win us back to the love of the good, than to grant us the evil. Not that it is wrong to eat flesh, for the apostle, speaking of this very thing, says, Every creature of God is good, and nothing to be refused which is received with thanksgiving; but because, as he also says, “It is evil for that man who eats with offense;” and if so, with offense to man, how much more so if to God, to whom it was no light offense, on the part of the Israelites, to reject what wisdom was supplying, and ask for that which lust was craving: although they would not actually make the request, but murmured because it was wanting. But to let us know that the wrong lies not with any creature of God, but with obstinate disobedience and inordinate desire, it was not in swine's flesh that the first man found death, but in an apple; and it was not for a fowl, but for a dish of pottage, that Esau lost his birthright.
2. How, then, are we to understand “Whatsoever you shall ask, I will do it,” if there are some things which the faithful ask, and which God, even purposely on their behalf, leaves undone? Or ought we to suppose that the words were addressed only to the apostles? Surely not. For what He has got the length of now saying is in the very line of what He had said before: “He that believes in me, the works that I do shall he do also; and greater works than these shall he do;” which was the subject of our previous discourse. And that no one might attribute such power to himself, but rather to make it manifest that even these greater works were done by Himself, He proceeded to say, “For I go to the Father; and whatsoever you shall ask in my name, I will do it.” Was it the apostles only that believed on Him? When, therefore, He said, “He that believes in me,” He spoke to those, among whom we also by His grace are included, who by no means receive everything that we ask. And if we turn our thoughts even to the most blessed apostles, we find that he who labored more than they all, yet not he, but the grace of God that was with him, besought the Lord thrice that the messenger of Satan might depart from him, and received not what he had asked. What shall we say, beloved? Are we to suppose that the promise here made, “Whatsoever you shall ask in my name, I will do it,” was not fulfilled by Him even to the apostles? And to whom, then, will ever His promise be fulfilled, if therein He has deceived His own apostles?
3. Wake up, then, believer, and give careful heed to what is stated here, “in my name:” for in these words He does not say, “whatsoever you shall ask” in any way; but, “in my name.” How, then, is He called, who promised so great a blessing? Christ Jesus, of course: Christ means King, and Jesus means Saviour! For certainly it is not any one who is a king that will save us, but only the Saviour-King; and therefore, whatsoever we ask that is adverse to the interests of salvation, we do not ask in the name of the Saviour. And yet He is the Saviour, not only when He does what we ask, but also when He refuses to do so; since by not doing what He sees to be contrary to our salvation, He manifests Himself the more fully as our Saviour. For the physician knows which of his patient's requests will be favorable, and which will be adverse, to his safety; and therefore yields not to his wishes when asking what is prejudicial, that he may effect his recovery. Accordingly, when we wish Him to do whatsoever we ask, let it not be in any way, but in His name, that is, in the name of the Saviour, that we present our petition. Let us not, then, ask anything that is contrary to our own salvation; for if He do that, He does it not as the Saviour, which is the name He bears to His faithful disciples. For He who condescends to be the Saviour of the faithful, is also a Judge to condemn the ungodly. Whatsoever, therefore, any one that believes in Him shall ask in that name which He bears to those who believe in Him, He will do it; for He will do it as the Saviour. But if one that believes in Him asks something through ignorance that is injurious to his salvation, he asks it not in the name of the Saviour; for His Saviour He will no longer be if He do anything to impede his salvation. And hence, in such a case, in not doing what He is entreated to do, His way is kept the clearer for doing what His name imports. And on that account, not only as the Saviour, but also as the good Master, He taught us, in the very prayer He gave us, what we should ask, in order that, whatsoever we shall ask, He may do it; and that we, too, might thereby understand that we cannot be asking in the Master's name anything that is inconsistent with the rule of His own instructions.
Source: Tractates on the Gospel of John (New Advent)