There is only one religion, though there are a hundred versions of it.
George Bernard Shaw, Plays Pleasant and Unpleasant (1898)
Although the central theme in Chapter 4 was how religions diffuse through space and time, many of the case studies and illustrations there highlighted just how dynamic things are. Shaw’s belief that there is only one religion is misplaced, because it overlooks the fundamental differences between religions and falsely assumes that they are all variations on an underlying common theme.
Few religions remain absolutely constant through time. Splits occur within individual religions, often promoted by differences of interpretation or practice which reform movements seek to restore to original forms. Good examples include the split in Christianity brought by the Reformation (Chapter 4, pp. 111-17), the split of Islam into Shiite and Sunni branches (Chapter 4, pp. 109-11), and the split of the Amish from the Mennonites (Chapter 4, pp. 123-7). Even where religions are not torn apart by schism, beliefs and practices can change through time particularly when a religion is planted in a new area. Cultural assimilation can include the absorption of indigenous beliefs and practices into the newly arrived (usually universalist) religion, which can thus evolve regional variants reflecting their unique cultural settings. The Black Christian Methodist Episcopal Church in North America (Chapter 4, pp. 117-18), for example, retains vestiges of its African genesis and its black slave heritage, although it still has great appeal in contemporary black American society.
In this chapter we examine some important dimensions of the dynamics of religions, in seeking to better understand how and why religions change. It is convenient to start by exploring patterns and processes of religious change.
Religious change involves both quantitative and qualitative changes, and in this section we will look at some of the empirical evidence of rates and patterns