Small though it may be, Unitarian Universalism has had a big impact not only on its members but also on the world around it. Rejecting the constraints of other Christian denominations, it sought tolerance for itself and, surprisingly, freely granted tolerance to others. Evolving in its principles and practices over a relatively short lifetime, it shows every sign of developing further, reaching beyond Christianity to embrace what is good in other, more diverse religions. Unitarian Universalism has also regularly been at the forefront in fighting for social causes, including abolition,...