Book 3, Chapter 10, Sections 1-3:
"...I indeed confess that here consciences neither can nor ought to be bound by fixed and definite laws; but that Scripture having laid down general rules for the legitimate uses we should keep within the limits which they prescribe.
"2. Let this be our principle, that we err not in the use of the gifts of Providence when we refer them to the end for which their author made and destined them, since he created them for our good, and not for our destruction. No man will keep the true path better than he who shall have this end carefully in view. Now then, if we consider for what end he created food, we shall find that he consulted not only for our necessity, but also for our enjoyment and delight. Thus, in clothing, the end was, in addition to necessity, comeliness and honour; and in herbs, fruits, and trees, besides their various uses, gracefulness of appearance and sweetness of smell. Were it not so, the Prophet would not enumerate among the mercies of God “wine that maketh glad the heart of man, and oil to make his face to shine,” (Ps. 104:15). The Scriptures would not everywhere mention, in commendation of his benignity, that he had given such things to men. The natural qualities of things themselves demonstrate to what end, and how far, they may be lawfully enjoyed. Has the Lord adorned flowers with all the beauty which spontaneously presents itself to the eye, and the sweet odour which delights the sense of smell, and shall it be unlawful for us to enjoy that beauty and this odour? What? Has he not so distinguished colours as to make some more agreeable than others? Has he not given qualities to gold and silver, ivory and marble, thereby rendering them precious above other metals or stones? In short, has he not given many things a value without having any necessary use?
"3. Have done, then, with that inhuman philosophy which, in allowing no use of the creatures but for necessity, not only maliciously deprives us of the lawful fruit of the divine beneficence, but cannot be realised without depriving man of all his senses, and reducing him to a block. But, on the other hand, let us with no less care guard against the lusts of the flesh, which, if not kept in order, break through all bounds, and are, as I have said, advocated by those who, under pretence of liberty, allow themselves every sort of license. First one restraint is imposed when we hold that the object of creating all things was to teach us to know their author, and feel grateful for his indulgence. Where is the gratitude if you so gorge or stupify yourself with feasting and wine as to be unfit for offices of piety, or the duties of your calling? Where the recognition of God, if the flesh, boiling forth in lust through excessive indulgences infects the mind with its impurity, so as to lose the discernment of honour and rectitude? Where thankfulness to God for clothing, if on account of sumptuous raiment we both admire ourselves and disdain others? if, from a love of show and splendour, we pave the way for immodesty? Where our recognition of God, if the glare of these things captivates our minds? For many are so devoted to luxury in all their senses that their mind lies buried: many are so delighted with marble, gold, and pictures, that they become marble-hearted—are changed as it were into metal, and made like painted figures. The kitchen, with its savoury smells, so engrosses them that they have no spiritual savour. The same thing may be seen in other matters. Wherefore, it is plain that there is here great necessity for curbing licentious abuse, and conforming to the rule of Paul, “make not provision for the flesh to fulfil the lusts thereof,” (Rom. 13:14). Where too much liberty is given to them, they break forth without measure or restraint."
In short, we ought to enjoy the gifts God has given to us, while not being so engrossed in them so as to forget the God that gave them. Don't be an ungrateful ascetic block, and don't be a selfish marble-hearted painted figure.