Of Prayer, by John Calvin, tr. Henry Beveridge , at sacred-texts.com
Both things are specially worthy of notice. First, let every one in professing to pray turn thither all his thoughts and feelings, and be not (as is usual) distracted by wandering thoughts; because nothing is more contrary to the reverence due to God than that levity which bespeaks a mind too much given to license and devoid of fear. In this matter we ought to labour the more earnestly the more difficult we experience it to be; for no man is so intent on prayer as not to feel many thoughts creeping in, and either breaking off the tenor of his prayer, or retarding it by some turning or digression. Here let us consider how unbecoming it is when God admits us to familiar intercourse to abuse his great condescension by mingling things sacred and profane, reverence for him not keeping our minds under restraint; but just as if in prayer we were conversing with one like ourselves forgetting him, and allowing our thoughts to run to and fro. Let us know, then, that none duly prepare themselves for prayer but those who are so impressed with the majesty of God that they engage in it free from all earthly cares and affections. The ceremony of lifting up our hands in prayer is designed to remind us that we are far removed from God, unless our thoughts rise upward: as it is said in the psalm, "Unto thee, O Lord, do I lift up my soul" (Psalm 25:1Psalm 25:1). And Scripture repeatedly uses the expression to raise our prayers meaning that those who would be heard by God must not grovel in the mire. The sum is, that the more liberally God deals with us, condescendingly inviting us to disburden our cares into his bosom, the less excusable we are if this admirable and incomparable blessing does not in our estimation outweigh all other things, and win our affection, that prayer may seriously engage our every thought and feeling. This cannot be unless our mind, strenuously exerting itself against all impediments, rise upward.
Our second proposition was, that we are to ask only in so far as God permits. For though he bids us pour out our hearts (Psalm 62:8), he does not indiscriminately give loose reins to foolish and depraved affections; and when he promises that he will grant believers their wish, his indulgence does not proceed so far as to submit to their caprice. In both matters grievous delinquencies are everywhere committed. For not only do many without modesty, without reverence, presume to invoke God concerning their frivolities, but impudently bring forward their dreams, whatever they may be, before the tribunal of God. Such is the folly or stupidity under which they labour, that they have the hardihood to obtrude upon God desires so vile, that they would blush exceedingly to impart them to their fellow men. Profane writers have derided and even expressed their detestation of this presumption, and yet the vice has always prevailed. Hence, as the ambitious adopted Jupiter as their patron; the avaricious, Mercury; the literary aspirants, Apollo and Minerva; the warlike, Mars; the licentious, Venus: so in the present day, as I lately observed, men in prayer give greater license to their unlawful desires than if they were telling jocular tales among their equals. God does not suffer his condescension to be thus mocked, but vindicating his own light, places our wishes under the restraint of his authority. We must, therefore, attend to the observation of John: "This is the confidence that we have in him, that if we ask anything according to his will, he heareth us" (1 John 5:14).
But as our faculties are far from being able to attain to such high perfection, we must seek for some means to assist them. As the eye of our mind should be intent upon God, so the affection of our heart ought to follow in the same course. But both fall far beneath this, or rather, they faint and fail, and are carried in a contrary direction. To assist this weakness, God gives us the guidance of the Spirit in our prayers to dictate what is right, and regulate our affections. For seeing "we know not what we should pray for as we ought," "the Spirit itself maketh intercession for us with groanings which cannot be uttered" (Romans 8:26) not that he actually prays or groans, but he excites in us sighs, and wishes, and confidence, which our natural powers are not at all able to conceive. Nor is it without cause Paul gives the name of groanings which cannot be uttered to the prayers which believers send forth under the guidance of the Spirit. For those who are truly exercised in prayer are not unaware that blind anxieties so restrain and perplex them, that they can scarcely find what it becomes them to utter; nay, in attempting to lisp they halt and hesitate. Hence it appears that to pray aright is a special gift. We do not speak thus in indulgence to our sloths as if we were to leave the office of prayer to the Holy Spirit, and give way to that carelessness to which we are too prone. Thus we sometimes hear the impious expression, that we are to wait in suspense until he take possession of our minds while otherwise occupied. Our meaning is, that, weary of our own heartlessness and sloth, we are to long for the aid of the Spirit. Nor, indeed, does Paul, when he enjoins us to pray in the Spirit (1 Corinthians 14:15), cease to exhort us to vigilance, intimating, that while the inspiration of the Spirit is effectual to the formation of prayer, it by no means impedes or retards our own endeavours; since in this matter God is pleased to try how efficiently faith influences our hearts.