Satan does some of his worst work on exhausted Christians when nerves are frayed and the mind is faint.
Vance HavnerIt is not that God is stingy and must be coaxed, for He "giveth liberally and upbraideth not." It is that we ourselves are so shallow and sinful that we need to tarry before Him until our restless natures can be stilled and the clamor of outside voices be deadened so that we can hear His voice. Such a state is not easily reached, and the men God uses have paid a price in wrestlings and prevailing prayer. But it is such men who rise from their knees confident of His power and go forth to speak with authority.
Vance Havner