If it is a duty to love God with all one's heart, mind, being and strength, then it seems that every action ought to be an expression of love for God. Therefore, every action is morally significant: it is either morally good, being an expression of love for God, or it fails to be an expression of love for God, and thus fails to be good. After all, if one acts not out of love for God, then one has a motivation that is not based on love for God, and hence one is failing to love God with all of one's will.
This could be read very pessimistically as the Lutheran claim that we are always sinning. But it could also be read more optimistically, as that many apparently insignificant actions, if they are not to be wicked, must actually be expressions of love for God.
Let me end with my favorite quote from George MacDonald (The Princess and Curdie):
'But, please, ma'am - I don't mean to be rude or to contradict you,' said Curdie, 'but if a body was never to do anything but what he knew to be good, he would have to live half his time doing nothing.'
'There you are much mistaken,' said the old quavering voice. 'How little you must have thought! Why, you don't seem even to know the good of the things you are constantly doing. Now don't mistake me. I don't mean you are good for doing them. It is a good thing to eat your breakfast, but you don't fancy it's very good of you to do it. The thing is good, not you.'
'There are a great many more good things than bad things to do. [...]'