Those who admit the truth of what I have said know, I am sure, why we are bound to love God. But if unbelievers will not grant it, their ingratitude is at once confounded by His innumerable benefits, lavished on our race, and plainly discerned by the senses. Who is it that gives food to all flesh, light to every eye, air to all that breathe? It would be foolish to begin a catalogue, since I have just called them innumerable: but I name, as notable instances, food, sunlight and air; not because they are God's best gifts, but because they are essential to bodily life. Man must seek in his own higher nature for the highest gifts; and these are dignity, wisdom and virtue. By dignity I mean free-will, whereby he not only excels all other earthly creatures, but has dominion over them. Wisdom is the power whereby he recognizes this dignity, and perceives also that it is no accomplishment of his own. And virtue impels man to seek eagerly for Him who is man's Source, and to lay fast hold on Him when He has been found.
Bernard of Clairvaux, On Loving God