Man was created to praise, reverence, and serve God our Lord and in this way to save his soul. The other things on Earth were created for man's use, to help him reach the end for which he was created.
Even in the angels there is the subordination of one hierarchy to another, and in the heavens, and all the bodies that are moved, the lowest by the highest and the highest in their turn unto the Supreme Mover of all.
It is not hard to obey when we love the one whom we obey.
It is certain that, because the negligent do not struggle against self, they never achieve peace of soul or do so tardily, and never possess any virtue in its fullness, while the energetic and industrious make notable advances on both fronts.