Linda Woodhead attempts to provide a common belief thread for Christians by noting that "Whatever else they might disagree about, Christians are at least united in believing that Jesus has a unique significance." Philosopher Michael Martin, in his book The Case Against Christianity, evaluated three historical Christian creeds (the Apostles' Creed, the Nicene Creed and the Athanasian Creed) to establish a set of basic assumptions which include belief in theism, the historicity of Jesus, the Incarnation, salvation through faith in Jesus, and Jesus as an ethical role model.