John Bunyan wrote, "Pray often, for prayer is a shield to the soul, a sacrifice to God, and a scourge for Satan."
How many of us have left our cell phone charger in a hotel somewhere or at the home of relatives? Without constant charging, the battery grows weak and the signal dies out. The same is true for our spiritual connection. It's great to be willing in spirit, but we have to remain "charged up" through the discipline of watchfulness and prayer.
Watching means we don't let ourselves drift into sin. Often when we're tired or we've worked for a long stretch without a break, we're more vulnerable to evil thoughts or inappropriate reactions. We should know ourselves well enough to think ahead and avoid unhealthy responses.
Praying means we have definite patterns and plans every day to talk with our Father without hurry or rush, and that we obey every impulse to pray throughout the day.
It's great when the spirit is willing, but the flesh requires the disciplines of watching and praying.
Always respond to every impulse to pray . . . . I would make an absolute law of this—always obey such an impulse. D. Martyn Lloyd-Jones