Of Prayer, by John Calvin, tr. Henry Beveridge , at sacred-texts.com
To prayer, then, are we indebted for penetrating to those riches which are treasured up for us with our heavenly Father. For there is a kind of intercourse between God and men, by which, having entered the upper sanctuary, they appear before Him and appeal to his promises, that when necessity requires they may learn by experiences that what they believed merely on the authority of his word was not in vain. Accordingly, we see that nothing is set before us as an object of expectation from the Lord which we are not enjoined to ask of Him in prayer, so true it is that prayer digs up those treasures which the Gospel of our Lord discovers to the eye of faith. The necessity and utility of this exercise of prayer no words can sufficiently express. Assuredly it is not without cause our heavenly Father declares that our only safety is in calling upon his name, since by it we invoke the presence of his providence to watch over our interests, of his power to sustain us when weak and almost fainting, of his goodness to receive us into favour, though miserably loaded with sin; in fine, call upon him to manifest himself to us in all his perfections. Hence, admirable peace and tranquillity are given to our consciences; for the straits by which we were pressed being laid before the Lord, we rest fully satisfied with the assurance that none of our evils are unknown to him, and that he is both able and willing to make the best provision for us.