A health teacher taught his students the importance of washing their hands before eating. He had them take scrapings from their fingers and put them in an environment that fosters the growth of bacteria. A few days later, they looked at the results through a microscope. The students found critters from their fingers that could have made them sick if they had eaten them with their dinner.

Many people who make sure they wash their hands before they eat are careless about a far more serious kind of contamination. They should heed the advice of Isaiah. He showed God's people the visible evidence of their evil condition. He pointed to their crumbling society and told them it was the result of their moral and spiritual pollution. They had lived for selfish rewards, ignored justice and mercy, and loved material possessions more than people. No wonder Isaiah exhorted them, "Wash yourselves, make yourselves clean" (Isa. 1:16).

Behind Isaiah's words is the heavenly Father's love. Because God can see the danger of sin, He points to its visible, physical results. He pleads with us to be as careful with what we take into our hearts and minds as we are with what we put into our mouths.  — Mart De Haan