At last they understood that He wasn’t speaking about the
yeast in bread, but about the deceptive teaching of the Pharisees and Sadducees.
(Matthew 16:12 NLT)
There has come into this universe something that disturbs the universe. All these terrible wars, about which you know something, are the result of this disturbing influence which has come into the universe. There is something in this universe that stirs up human nature. Like alcohol, it makes men fight against one another. It keeps the world in unrest. It produces all this excitement of the human evil nature. Then, again, this something that has come into this universe results in an enlargement that is quite unnatural – a false development.... Anything that results in unnatural development and enlargement is evil. The Apostle Paul said, "Through the grace given unto me, to every man that is among you, not to think of himself more highly than he ought to think; but to think soberly, according as God hath dealt to every man the measure of faith." Anything that makes us unnaturally big is evil, whether it be the individual life, or whether it be what is called the work of God, trying to make it bigger than its real spiritual measure, inflating it beyond its genuine spiritual degree; that is something evil, that is leaven....
Then what about this leaven
that makes things appeal to our natural taste? Paul said to Timothy, "The time
will come when they will not endure sound teaching; and they will heap to
themselves teachers, having itching ears." And he goes on to say that they will
believe the lie instead of the truth. Why is that? Because these teachers appeal
to the natural life. These teachers cover over evil. Indeed, they will sometimes
call evil good. People do not like the teachers who tell them what is wrong,
that this thing and that thing are contrary to God. They like leavened bread, it
pleases the flesh.... He says there will be leaven, there will be corruption and
defilement everywhere, but the teaching of the New Testament is: Keep yourselves
pure. See that your garments are not spotted. Walk in this sinful world as those
who do not belong to its nature. Although there is leaven everywhere, you be the
unleavened bread. But, the world may not like you, the world will not like
unleavened bread. It does not please the flesh, but the bread which is pure is
pleasing to God.