I’m finding P.T. Forsyth’s The Soul of Prayer full of insightful meditations on the joys and travails of prayer. He rightly says prayerlessness is the equivalent to spiritual starvation. To carry the metaphor further the Scotsman writes,

Prayer brings with it, as food does, a new sense of power and health. We are driven to it by hunger, and, having eaten, we are refreshed and strengthened for the battle which even our physical life involves. For heart and flesh cry out for the living God.

We must work for this living. To feed the soul we must toil at prayer. And what a labour it is! “He prayed in an agony.” We must pray even to tears if need be. Our cooperation with God is our receptivity; but it is an active, a laborious receptivity, an importunity that drains our strength away if it do not tap the sources of the Strength Eternal. We work, we slave, at receiving. To him that hath this laborious expectancy it shall be given. Prayer is the powerful appropriation of power, of divine power.

Blessed are those who hunger, for they shall be satisfied.