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 short-sighted wisdom. Although THE SINFULNESS OF SIN was written three hundred years ago, it remains an oasis of truth in a desert of lies. This book gives a clear explanation of what sin is, why it is so serious, and what we need to do about it.