Of Prayer, by John Calvin, tr. Henry Beveridge [1845], at sacred-texts.com
By this, however, we would not have it understood that we are so restricted to this form of prayer as to make it unlawful to change a word or syllable of it. For in Scripture we meet with many prayers differing greatly from it in word, yet written by the same Spirit, and capable of being used by us with the greatest advantage. Many prayers also are continually suggested to believers by the same Spirit, though in expression they bear no great resemblance to it. All we mean to say is, that no man should wish, expect, or ask anything which is not summarily comprehended in this prayer. Though the words may be very different, there must be no difference in the sense. In this way, all prayers, both those which are contained in the Scripture, and those which come forth from pious breasts, must be referred to it, certainly none can ever equal it, far less surpass it in perfection. It omits nothing which we can conceive in praise of God, nothing which we can imagine advantageous to man, and the whole is so exact that all hope of improving it may well be renounced. In short, let us remember that we have here the doctrine of heavenly wisdom. God has taught what he willed; he willed what was necessary.