The word of our God endures forever.

That is, it holds firm, is certain, does not waver, does not flinch, does not sink, does not lack, does not miss. Where this word comes into the heart with right faith, it makes the heart firm, sure and certain, so that it becomes stiff, upright and hard against all temptation, the devil, death and whatever it may be called, that it defiantly and arrogantly despises and mocks everything that wants to be doubtful, hesitant, evil and angry, because it knows that God's word cannot lie to it.