"So what do you believe?" It's the question Quakers are always asked first and the one they find hardest to answer, because they don't have an official list of beliefs. And Quakerism is a religion of doing, not thinking. They base their lives on equality and truth; they work for peace, justice and reconciliation; they live adventurously. And underpinning their unique way of life is a spiritual practice they have sometimes been wary of talking about...