It is, therefore, by the benefit of prayer that we reach those riches which are laid up for us with the Heavenly Father. For there is a communion of men with God by which, having entered the heavenly sanctuary, they appeal to him in person concerning his promises in order to experience, where necessity so demands, that what they believed was not vain, although he had promised it in word alone. Therefore we see that to us nothing is promised to be expected from the Lord, which we are not also bidden to ask of him in prayers.John Calvin, Institutes, 3.20.2
First, that our hearts may be inflamed with continual fear, honor, and love of God, to whom we run for support and help whensoever danger or necessity requires; that we so learning to [make known] our desires in His presence, He may teach us what is to be desired, and what not.
Second, that we, knowing our petitions to be granted by God alone (to Him only we must render and give laud and praise), and that we, ever having His infinite goodness fixed in our minds, may constantly abide to receive that which with fervent prayer we desire.John Knox, “A Treatise on Prayer,” in Select Writings, 75.