Many, perhaps most, who see the title of this book will at once traverse it, and will deny that there is anything valuable which can be rightly described as "Esoteric Christianity." There is a wide-spread, and withal a popular, idea that there is no such thing as an occult teaching in connection with Christianity, and that "The Mysteries," whether Lesser or Greater, were a purely Pagan institution. The very name of "The Mysteries of Jesus," so familiar in the ears of the Christians of the first centuries, would come with a shock of surprise on those of their modern successors, and, if spoken as denoting a special and definite institution in the Early Church, would cause a smile of incredulity.