From these precepts it is evident that our every action should be directed towards the attainment of an interior life, which alone giveth true happiness. For if contrariwise we seek our reward in outward things, we shall be conformed to the fashion of this world, and thus forfeit God's promise of happiness, to wit, that we shall be conformed to the image of his Son. Such happiness, inasmuch as it concerneth inward things, is all the more certain and enduring. Howbeit, the special teaching of this passage is this: That vainglory can come forth, not only from worldly elegance and human pretensions, but even from a condition of sad countenance and dirty disfigurement. Furthermore, the latter kind of vainglory is the more dangerous, in that it deceiveth under the pretence of an humble service of God.
On the one hand, whosoever sheweth unbridled indulgence, whether in bodily comforts and dress, or in other forms of elegance, thereby standeth manifestly convicted as a follower of the pomps of this world. Nor doth such an one, by his pretence of godliness, deceive anybody. On the other hand, whosoever from choice, and not of necessity, professeth Christianity in such wise as to draw attention unto himself by reason of his seeming humility, or his particular disregard for outward things, this man is to be judged from the fashion of his other behaviour, as to whether therein he sheweth a desire for mortification, or rather for vainglory. For the Lord biddeth us beware of wolves in sheep's clothing. Rather, as he saith, by their fruits shall ye know them.
Now here is the test of the seeming godliness of such folk. When some adversity bringeth upon them the loss of the advantages which they had gained, or sought to gain, by their profession of godliness, then it must needs appear whether they be wolves in sheep's clothing, or sheep in their own. Nevertheless, a Christian should not seek to tickle the fancy of other folk by a parade of elegance, on the plea that hypocrites do seek to beguile the unwary by a display of frugality. For sheep should not lay aside their own clothing because wolves do sometimes falsely assume the same.