“As the heart must be lifted up by the Spirit, if it pray aright, so also it must be held up the Spirit when it is up, if it is to continue to pray aright. I do not know what or how it is with others’ hearts, whether they be lifted up by the Spirit of God, and so continued, or no: but this I am sure of, first, that it is impossible that all the prayer books that men have in the world, should lift up, or prepare the heart, for that is the work of the great God himself. And, in the second place, I am sure that they are as far from keeping it up, when it is up. And indeed here is the life of prayer, to have the heart kept with God in the duty. It was a great matter for Moses to keep his hands lifted up to God in prayer; but how much more then to keep the heart in it! (Exod. 17:12).
The want of this is that which God complains of; that men draw nigh to him with their mouth, and know him with their lips, but their hearts are far from him (Is. 29:13; Ezek. 33:31), but chiefly they that walk after the commandments and traditions of men, as the scope of Matthew 15:8-9 testifies. And verily, may I but speak my own experience, and from that tell you the difficulty of praying to God as I ought, it is enough to make your poor, blind, carnal men to entertain strange thoughts of me. For, as for my heart, when I go to pray, I find it so loth to go to God, and when it is with him, so loth to stay with him, that many times I am forced in my prayers, first to beg of God that he would take mine heart, and set it on himself in Christ, and when it is there, that he would keep it there. Nay, many times I know not what to pray for, I am so blind, nor how to pray, I am so ignorant; only blessed be grace, the Spirit helps our infirmities (Ps. 86:11).
O the starting-holes that the heart has in the time of prayer! None knows how many by-ways the heart has, and back-lanes, to slip away from the presence of God. How much pride also, if enabled with expressions! How much hypocrisy, if before others! And how little conscience is there made of prayer between God and the soul in secret, unless the Spirit of supplication be there to help! When the Spirit gets into the heart, then there is prayer indeed, and not till then.”
– John Bunyan, Prayer, p.31-32