House of Knox

Trouble and fear are the very spurs to prayer; for when man, compassed about with vehement calamities, and vexed with continual solicitude (having, by help of man, no hope of deliverance, with sorely oppressed and punished heart, fearing also greater punishment to follow), does call to God for comfort and support from the deep pit of tribulation, such prayer ascends into God's presence, and returns not in vain.

John Knox, Treatise on Prayer