Those who work at a thing heart and soul not only achieve success in it but through their absorption in that they also realize the supreme truth-Brahman. Those who work at a thing with their whole heart receive help from God.
Excellence is an art won by training and habituation. We do not act rightly because we have virtue or excellence, but we rather have those because we have acted rightly. We are what we repeatedly do. Excellence, then, is not an act but a habit.