This book is written to help Christians from different traditions better understand each other. It is written from a perspective that unity in essentials can be a basis for liberty in non-essentials. From this shared foundation of basic, or what C.S. Lewis called "mere", Christianity, the book explores how the differences between the various traditions arise. It promotes a view that many of these secondary differences in theology, spirituality and practice arise as gifts that the Holy Spirit gave to particular communities to help them in particular circumstances. This view enables a more positive attitude to be expressed, and gives scope that our differences might be gifts to share, rather than causes of division. Written to be accessible to a lay readership, it is also suited to those commencing studies in this area by the addition of detailed end notes.