We cannot understand the Christian gospel until we know what sin is. Yet modern secular counsellors urge us to ignore both the word and what it tells us about our rebellion against God and his law. Sadly, the church too often serves as an echo chamber for such cheap and short-sighted wisdom. It's literature spreads the deceptive message that all is well. But it is only when we begin to see our sinfulness that we are able to discover God's forgiveness. Although The Sinfulness of Sin was written three hundred years ago, it remains an oasis of truth in a desert of lies. First published in the aftermath of the Great Plague of London and entitled Sin, The Plague of Plagues, this book gives a crystal-clear explanation of what sin is, why it is so serious, and what we need to do about it. Here is reliable medicine for a fatal epidemic.