We have all become like one who is unclean, and all our righteous deeds are like a filthy cloth. We all fade like a leaf, and our iniquities, like the wind, take us away.
Isaiah 64:6 NRSV
Perhaps the most significant consequence of sin, as they recognize, is that it makes us unclean (v. 6) in the presence of the One who is absolutely clean. This powerful metaphor runs through the Bible. Clean and unclean are opposites; the one cannot exist in the presence of the other. If there are two surgeons operating on a patient, and one is thoroughly clean, while the other has not taken the time to scrub, the patient’s wound will become contaminated. Long before anyone understood the necessity for sterility in the operating room the Biblical writers understood the contaminating power of sin. For the pagans, “clean” and “unclean” was a matter of exorcising evil powers so that rituals would be effective. Not so in the Bible. It is the damning power of self that makes it impossible for us creatures to co-exist with God. This explains that profound statement in v. 6. How can doing what is right make us filthy? Very simply, it is when we do those right things for the wrong motives and purposes. We may give a large sum of money to our church. That is certainly the “right” thing to do. But why have we done it? Is it because we unselfishly love God and others? Or is it because selfishly we want to be known to ourselves (and probably to others) as very generous persons?