What the Bible says about Defiling Sins Spring from Heart
(From Forerunner Commentary)
What is Jesus trying to tell us? "Work on yourself!" He advises. The evils we have to recognize, face down, and obliterate are inside. They are the defiling sins that spring from our "deceitful . . . and desperately wicked" heart (Jeremiah 17:9). If we really want to clean up society and deny Satan victory over us, our job is to root out the evils within.
Richard T. Ritenbaugh
Evil Is Real (Part Three)