Holy, be ye also holy in all your conduct, as it is written, Be ye
holy for I am Holy._

This is an admonition to faith, and the sense is this: while such
things are preached to you and bestowed upon you through the Gospel
as the angels would rejoice and be desirous to behold, rely on them,
and fix your confidence thereon with all firmness, so that it shall
be a real faith, and not a painted or fictitious fancy or dream.

_Gird up the loins of your mind._ Here Peter speaks of a spiritual
girding of the mind, just as one girds his sword to the loins of his
body. This girding has Christ also enforced, Luke xii., where he
says, "Let your loins be girt about." In some places the Scriptures
speak of the loins with reference to bodily lust; but here St. Peter
speaks of the loins of the spirit. As to the body, Scripture speaks
of the loins with reference to natural generation from the father; as
we read, Genesis xlix., that from the loins of Judah Christ should
come. Likewise the bodily girding of the loins is the same with
chastity, as Isaiah says, chapter xi., "Righteousness shall be the
girdle of his loins, and faith the girdle of his reins." That is,
only by faith is wicked lust subdued and restrained.

But this spiritual girding, whereof the Apostle speaks, means more.
As a virgin is pure and inviolate in body, so is the soul spiritually
inviolate through faith, by which it becomes Christ's bride. But if
it falls from faith into false doctrine, it must be brought to shame.
Hence Scripture uniformly calls impiety and unbelief, adultery and
whoredom,--that is, when the soul relies on human doctrines, and thus
lets go its hold on faith and Christ. This St. Peter here forbids,
when he calls on us to gird up the loins of our mind; as though he
would say, ye have now heard the Gospel and have come to believe,
therefore see to it that ye abide therein, and do not suffer
yourselves to be drawn away with false doctrine, so that ye shall not
waver and run hither and thither with works.

And here he adopts a peculiar mode of speech, not after the manner of
St. Paul, where he speaks of "the loins of your mind." He calls
_that_ mind here which we speak of as disposition; as when I say,
"This seems to me right and as Paul speaks, so we understand it, so
we are _disposed_." In this he refers especially to faith, and would
say: ye have attained a correct apprehension that we must be
justified through faith; abide in that mind; g