John Piper, Brothers, We Are Not Professionals, Bethlehem Baptist Church, 2002. p. 60.
Without extended, concentrated prayer, the ministry of the Word withers. And when the ministry of the Word declines, faith (Rom. 10:17; Gal. 3:2, 5) and holiness (John 17:17) decline. Activity may continue, but life and power and fruitfulness fade away. Therefore, whatever opposes prayer opposes the whole work of ministry.
John Piper, Brothers, We Are Not Professionals, Bethlehem Baptist Church, 2002. p. 60.