with internals, not with externals.

Conformity to the world in most externals is not only advisable but
necessary. We wear clothing as the world does; we live in houses built
like those around us; we speak the same language as sinners; we have the
same habits of thought and speech in general that they have; we use the
same implements and tools; we raise the same crops; we employ the same
methods of work and business; in fact, we conform to the world in all
these things. We can not avoid doing this without sacrificing what is
vital and proper in our lives. Conformity to the world in these externals
becomes evil only when such conformity has its origin in an evil principle
in the heart or when it produces an evil effect.

When Christ prayed for his disciples, he said, "Keep them from the evil."
Paul said, "As using and not abusing." It is that which is evil, or the
evil use that is made of externals, that is obnoxious to God. A proper use
of all things is permissible, and if our hearts are conformed to God, we
naturally desire and seek only the proper use of things. But the natural
heart is wicked; it is set on pleasing itself; it is full of vanity and
pride. So long as this condition exists, the heart is not conformed to
God. There must be a transformation, and this is not one which starts from
the outside and works inward, for such at best could be only a
reformation. The real transformation is a thing that begins on the inside
and works a vital change in the spiritual condition and character. When
this internal change is wrought, it gives a new quality and direction to
the whole range of thought and activity. It manifests itself in new
desires and aspirations, in new habits and customs, in newness of speech
and looks and behavior. When we are transformed so that we become new
creatures in Christ Jesus, we begin to act like new creatures. But our
bodies are not transformed: we still have bodies of flesh, which retain
their natural desires and appetites, and these we may gratify in a lawful
way without sin.

When the heart is transformed and purified from its vanity and pride,
these qualities will not be manifested in external things. But so long as
pride and vanity remain in the heart, preaching to people and requiring
them to cease wearing worldly adornment is like trying to kill a tree by
pulling off some of its leaves--the people may layoff such things under
pressure, but they are no better than before. People mus