Of Prayer, by John Calvin, tr. Henry Beveridge , at sacred-texts.com
All things that we ought, indeed all that we are able, to ask of God, are contained in this formula, and as it were rule, of prayer delivered by Christ, our divine Master, whom the Father has appointed to be our teacher, and to whom alone he would have us to listen (Matthew 17:5). For he ever was the eternal wisdom of the Father, and being made man, was manifested as the Wonderful, the Counsellor (Isaiah 11:2; Isaiah 9:6). Accordingly, this prayer is complete in all its parts, so complete, that whatever is extraneous and foreign to it, whatever cannot be referred to it, is impious and unworthy of the approbation of God. For he has here summarily prescribed what is worthy of him, what is acceptable to him, and what is necessary for us; in short, whatever he is pleased to grant. Those, therefore, who presume to go further and ask something more from God, first seek to add of their own to the wisdom of God (this it is insane blasphemy to do); secondly, refusing to confine themselves within the will of God, and despising it, they wander as their cupidity directs; lastly, they will never obtain anything, seeing they pray without faith. For there cannot be a doubt that all such prayers are made without faith, because at variance with the word of God, on which if faith do not always lean it cannot possibly stand. Those who, disregarding the Master's rule, indulge their own wishes, not only have not the word of God, but as much as in them lies oppose it. Hence Tertullian (De Fuga in Persecutione) has not less truly than elegantly termed it Lawful Prayer, tacitly intimating that all other prayers are lawless and illicit.