Of Prayer, by John Calvin, tr. Henry Beveridge [1845], at sacred-texts.com
If it is objected, that the necessity which urges us to pray is not always equal, I admit it, and this distinction is profitably taught us by James: " Is any among you afflicted? let him pray. Is any merry? let him sing psalms" (James 5:13). Therefore, common sense itself dictates, that as we are too sluggish, we must be stimulated by God to pray earnestly whenever the occasion requires. This David calls a time when God "may be found" (a seasonable time); because, as he declares in several other passages, that the more hardly grievances, annoyances, fears, and other kinds of trial press us, the freer is our access to God, as if he were inviting us to himself. Still not less true is the injunction of Paul to pray "always" (Ephesians 6:18); because, however prosperously according to our view, things proceed, and however we may be surrounded on all sides with grounds of joy, there is not an instant of time during which our want does not exhort us to prayer. A man abounds in wheat and wine; but as he cannot enjoy a morsel of bread, unless by the continual bounty of God, his granaries or cellars will not prevent him from asking for daily bread. Then, if we consider how many dangers impend every moment, fear itself will teach us that no time ought to be without prayer. This, however, may be better known in spiritual matters. For when will the many sins of which we are conscious allow us to sit secure without suppliantly entreating freedom from guilt and punishment? When will temptation give us a truce, making it unnecessary to hasten for help? Moreover, zeal for the kingdom and glory of God ought not to seize us by starts, but urge us without intermission, so that every time should appear seasonable. It is not without cause, therefore, that assiduity in prayer is so often enjoined. I am not now speaking of perseverance, which shall afterwards be considered; but Scripture, by reminding us of the necessity of constant prayer, charges us with sloth, because we feel not how much we stand in need of this care and assiduity. By this rule hypocrisy and the device of lying to God are restrained, nay, altogether banished from prayer. God promises that he will be near to those who call upon him in truth, and declares that those who seek him with their whole heart will find him: those, therefore, who delight in their own pollution cannot surely aspire to him.
One of the requisites of legitimate prayer is repentance. Hence the common declaration of Scripture, that God does not listen to the wicked; that their prayers, as well as their sacrifices, are an abomination to him. For it is right that those who seal up their hearts should find the ears of God closed against them, that those who, by their hardheartedness, provoke his severity should find him inflexible. In Isaiah he thus threatens: "When ye make many prayers, I will not hear: your hands are full of blood" (Isaiah 1:15). In like manner, in Jeremiah, "Though they shall cry unto me, I will not hearken unto them" (Jer. 11:7, 8, 11Jer. 11:7, 8, 11); because he regards it as the highest insult for the wicked to boast of his covenant while profaning his sacred name by their whole lives. Hence he complains in Isaiah: "This people draw near to me with their mouth, and with their lips do honour me; but have removed their heart far from men" (Isaiah 29:13). Indeed, he does not confine this to prayers alone, but declares that he abominates pretense in every part of his service. Hence the words of James, "Ye ask and receive not, because ye ask amiss, that ye may consume it upon your lusts" (James 4:3). It is true, indeed (as we shall again see in a little), that the pious, in the prayers which they utter, trust not to their own worth; still the admonition of John is not superfluous: "Whatsoever we ask, we receive of him, because we keep his commandments" (1 John 3:22); an evil conscience shuts the door against us. Hence it follows, that none but the sincere worshippers of God pray aright, or are listened to. Let every one, therefore, who prepares to pray feel dissatisfied with what is wrong in his condition, and assume, which he cannot do without repentance, the character and feelings of a poor suppliant.