Unless we believe the gospel, we will be driven in all we do-whether obeying or disobeying-by pride ('self-love') or fear ('of damnation'). Apart from 'grateful remembering' of the gospel, all good works are done then for sinful motives. Mere moral effort may restrain the heart, but does not truly change the heart. Moral effort merely 'jury rigs' the evil of the heart to produce moral behavior out of self-interest. It is only a matter of time before such a thin tissue collapses.
Timothy KellerTo take a person out of slavery takes an instant. To take slavery out of a person takes a process.
Timothy KellerGod made you to love him supremely, but he lost you. He returned to get you back, but it took the cross to do it. He absorbed your darkness so that one day you can finally and dazzlingly become your true self and take your seat at his eternal feast.
Timothy Keller