4 Our Lord then first of all cut off “much speaking,” that you might not bring a multitude of words unto God, as though by your many words you would teach Him. Therefore when you pray you have need of piety, not of wordiness. “For your Father knows what is needful for you, before ye ask Him.” Be loth then to use many words, for He knows what is needful for you. But lest perhaps any should say here, If He know what is needful for us, why should we use so much as a few words? Why should we pray at all? He knows Himself; let Him then give what He knows to be needful for us. Yes, but it is His will that you should pray, that He may give to your longings, that His gifts may not be lightly esteemed; seeing He has Himself formed this longing desire in us. The words therefore which our Lord Jesus Christ has taught us in His prayer, are the rule and standard of our desires. You may not ask for anything but what is written there.
5. “Do ye therefore say,” says he, “Our Father, which art in heaven.” Where ye see you have begun to have God for your Father. You will have Him, when you are new born. Although even now before you are born, you have been conceived of His seed, as being on the eve of being brought forth in the font, the womb as it were of the Church. “Our Father, which art in heaven.” Remember then, that you have a Father in heaven. Remember that you were born of your father Adam unto death, that you are to be born anew of God the Father unto life. And what ye say, say in your hearts. Only let there be the earnest affection of prayer, and there will be the effectual answer of Him who hears prayer. “Hallowed be your Name.” Why do you ask, that God's Name may be hallowed? It is holy. Why then do you ask for that which is already holy? And then when you ask that His Name may be hallowed, do you not as it were pray to Him for Him, and not for yourself? No. Understand it aright, and it is for your own self you ask. For this you ask, that what is always in itself holy, may be hallowed in you. What is “be hallowed?” “Be accounted holy,” be not despised. So then you see, that the good you wish, you wish for your own self. For if you despise the Name of God, for yourself it will be ill, and not for God.
6. “Your kingdom come.” To whom do we speak? And will not God's kingdom come, if we ask it not. For of that kingdom do we speak which will be after the end of the world. For God has a kingdom always; neither is He ever without a kingdom, whom the whole creation serves. But what kingdom then do you wish for? That of which it is written in the Gospel, “Come, you blessed of My Father, receive the kingdom which is prepared for you from the beginning of the world.” Lo here is the kingdom whereof we say, “Your kingdom come.” We pray that it may come in us; we pray that we may be found in it. For come it certainly will; but what will it profit you, if it shall find you at the left hand? Therefore, here again it is for your own self that you wish well; for yourself you pray. This it is that you long for; this desire in your prayer, that you may so live, that you may have a part in the kingdom of God, which is to be given to all saints. Therefore when you say, “Your kingdom come,” you pray for yourself, that you may live well. Let us have part in Your kingdom: let that come even to us, which is to come to Your saints and righteous ones.
7. “Your will be done.” What! If you say not this, will not God do His will? Remember what you have repeated in the Creed, “I believe in God the Father Almighty.” If He be Almighty, why do you pray that His will may be done? What is this then, “Your will be done”? May it be done in me, that I may not resist Your will. Therefore here again it is for yourself you pray, and not for God. For the will of God will be done in you, though it be not done by you. For both in them to whom He shall say, “Come, you blessed of My Father, receive the kingdom prepared for you from the beginning of the world;” shall the will of God be done, that the saints and righteous may receive the kingdom; and in them to whom He shall say, “Depart ye into everlasting fire, prepared for the devil and his angels,” shall the will of God be done, that the wicked may be condemned to everlasting fire. That His will may be done by you is another thing. It is not then without a cause, but that it may be well with you, that you dost pray that His will may be done in you. But whether it be well or ill with you, it will still be done in you: but O that it may be done by you also. Why do I say then, “Your will be done in heaven and in earth,” and do not say, “Your will be done by heaven and earth?” Because what is done by you, He Himself does in you. Never is anything done by you which He Himself does not in you. Sometimes, indeed, He does in you what is not done by you; but never is anything done by you, if He do it not in you.
Source: Sermons on Selected Lessons of the New Testament (New Advent)