Come to prayer…

Come to prayer, and bring your whole self with you. Do not let your mind remain in the market with your business. … Bring it back, so that it may come in and ask for its life. Do not stand half in and half out, or your prayer may get lost between the two parts. Stand at prayer united and complete, a true human, and then you can receive whatever you ask from God.
–Jacob of Serugh (c. 451-521)

The devil dreads…

The devil dreads fasting, prayer, humility, and good works: he is not able even to stop my mouth who speak against him. The illusions of the devil soon vanish, especially if a man arms himself with the Sign of the Cross. The devils tremble at the Sign of the Cross of our Lord, by which He triumphed over and disarmed them.
–Saint Anthony of Egypt (c. 251-356)