Sermon illustrations are a powerful means of communication when they do the job well; used naively they can be seriously misleading. The preacher began his "Children's Address" in an arresting fashion. Without a word, he set in motion a vacuum cleaner (which lay conveniently close to hand.) He told the children, and reminded the older generation of adults, of an early television advert in which a door-to-door salesman was allowed, by an alarmingly obliging housewife, to decorate her hitherto clean carpet with a variety of pre-packaged dirt. This dirt was then comprehensively despatched by the cleaner which, some may remember, "beats as it sweeps as it cleans".