This work is designed especially for people who have not the time nor the means to become thoroughly informed in matters of church history; and also for itinerant ministers and Bible workers, who, even though they be well read, can not carry a theological library with them from which to quote in time of need. It is hoped, also, that the book may serve as an incentive to some to make a systematic study of church history, and may aid them in so doing. And it is not impossible that the grouping of subjects may suggest new ideas, even to those who have read the entire history of the early church. Indeed, the book is mainly suggestive, the most exhaustive portion being the chapter on Sun-wor ship and Sunday. History repeats itself; and only he who knows the course of error in the past can be on his guard against its insidious approaches in the future.