For thine is the kingdom, the power and the glory, for ever and ever. Amen.
John Calvin
Moreover, there is subjoined the reason for our great boldness in asking and confidence of obtaining (sec. 11, 36). Although this does not exist in the Latin copies, yet as it accords so well with the whole, we cannot think of omitting it. The words are, THINE IS THE KINGDOM, AND THE POWER, AND THE GLORY, FOR EVER. Here is the calm and firm assurance of our faith. For were our prayers to be commended to God by our own worth, who would venture even to whisper before him? Now, however wretched we may be, however unworthy, however devoid of commendation, we shall never want a reason for prayer, nor a ground of confidence, since the kingdom, power, and glory, can never be wrested from our Father. The last word is AMEN, by which is expressed the eagerness of our desire to obtain the things which we ask, while our hope is confirmed, that all things have already been obtained and will assuredly be granted to us, seeing they have been promised by God, who cannot deceive. This accords with the form of expression to which we have already adverted: “Grant, O Lord, for thy name’s sake, not on account of us or of our righteousness.” By this the saints not only express the end of their prayers, but confess that they are unworthy of obtaining did not God find the cause in himself and were not their confidence founded entirely on his nature.
John Chrysostom
Having then made us anxious by reminding us of the enemy, and having cut away from us all our sins; He now encourages and raises our spirits. He reminds us of the King under whom we are arrayed who is more powerful than all. "For Thine," saith He, "is the kingdom, and the power, and the glory." If His be the kingdom, we should fear no one, since none can withstand him or take away his empire. For when He says, "Thine is the kingdom," He shows us that Satan has been brought into subjection, even though God permits him to oppose us for a while. In truth Satan too is God's servant, (though degraded and guilty of offense) and he would not dare attack any of his fellow servants, had he not first received permission from God.
And when when he says "And the power," you may be confident, however obvious your own weakness, because you have such a one to reign over thee, who is able easily and fully to accomplish all.
"And the glory, for ever. Amen." See, God not only frees you from the dangers that are approaching you, but can make you also glorious and illustrious. For His power is great, and His glory unspeakable, and they are all boundless and infinite. He has anointed His Champion in every way, and has framed Him to be full of confidence.
The conclusion of this divine prayer, commonly called the Doxology, is a solemn thanksgiving, and a complete acknowledgement of the attributes and works of God.
"For thine is the kingdom:" God, you have sovereign right over all things that are and ever were. Your kingdom is everlasting and your rule will endure throughout all ages.
“The power:” God, you are the governor of all things. You does whatever pleases you in all places.
"And the glory:" God, all creatures owe you praise for your power and might, and for all your wonderful works which you have done, and will do, world without end, "for ever and ever! Amen!"