So far this “pray without ceasing” from being absurd because extravagant that every man’s life is in some sense a continual state of prayer. For what is his life’s prayer but its ruling passion? All energies, ambitions and passions are but expressions of a standing nisus in life, of a hunger, a draft, a practical demand upon the future, upon the unattained and the unseen. Every life is a draft upon the unseen. If you are not praying towards God you are towards something else. You pray as your face is set--towards Jerusalem or Babylon. The very egotism of craving life is prayer. The great difference is the object of it. To whom, for what, do we pray? The man whose passion is habitually set upon pleasure, knowledge, wealth , honour, or power is in a state of prayer to these things or for them. He prays without ceasing. These are his real gods, on whom he waits day and night. He may from time to time go on his knees in church, and use words of Christian address and petition. He may even feel a momentary unction in so doing. But it is a flicker; the other devotion is his steady flame. His real God is the ruling passion and steady pursuit of his life taken as a whole. He certainly does not pray in the name of Christ. And what he worships in spirit and in truth is another God than he addresses at religious times. He prays to an unknown God for a selfish boon. Still, in a sense, he prays. The set and drift of his nature prays. It is the prayer of instinct, not of faith. It is prayer that needs total conversion. But he cannot stop praying either to God or to God’s rival--to self, society, world, flesh, or even devil. Every life that is not totally inert in praying either to God or God’s adversary.
P T Forsyth, in The Soul of Prayer, chapter 5