comparisons between denominations must be approached with caution. for example, some churches are part of a larger church organization or diocese, while in other groups, each congregation is an independent organization. this issue is further complicated by the existence of groups of congregations with a common heritage that are officially nondenominational and have no centralized authority or records, but which are identified as denominations by non-adherents. study of such churches in denominational terms is therefore a more complex proposition.