Theories supporting the integrative role of religion have been questioned mainly on the ground that in complex and multi-religious societies, doctrinal differences between denominations result in differences in social behavior, thus contributing to a lack of integration. The present data indicate that, at least in reference to American businessmen and the American business creed, acceptance of the differences among denominations are not determined directly by differences in doctrines, but by social processes operating independent from these doctrines. Serving as a mechanism of boundary maintenance and integration, the particular doctrine helps the denominational social system become autonomous and responsive to other systems. Because denominational social systems have different status, size and rate of growth, interaction among them is instrumental and leads to the development of secular rationalities such as the acceptance of the business creed, which operate independent from the doctrine and help them adjust themselves to each other and to the larger society.