“A spiritual growth, constant and sure spiritual development, is the surest safeguard against Satan's wiles, assaults and surprises. Constant growth is all eyes and all strength. Satan never finds it asleep, drowsy nor weak. Onward, upward, is the great battle cry. Constant advance is the steel armour in the fight with the devil.”E. M. Bounds
Source
E. M. Bounds, Satan: His Personality, Power and Overthrow Exact original-source attribution has not been independently verified.