The inner man cannot be forced to do out of his own free will, what he should do, except the grace of God change the heart and make it willing.
Martin LutherWhere faith is not continually kept in motion and exercised, it weakens and decreases, so that it must indeed vanish; and yet we do not see nor feel this weakness ourselves, except in times of need and temptation, when unbelief rages too strongly; and yet for that very reason faith must have temptations in which it may battle and grow.
Martin Luther