"One may not be able to afford the luxuries of food and drink, and yet, in a simple and innocent way, be guilty of gluttony by the mere fact that he is not eating for the sake of Heaven.
Similarly, a person may be clothed in gold and silk and partake of the greatest delicacies, but he may be doing so as a mode of Divine worship, in purity and in holiness."
--Rabbi Adin Steinsaltz
From Pebbles of Wisdom from Rabbi Adin Steinsaltz (forthcoming)
