<P> Well into the 20th century, Catholics--even if no longer resorting to persecution--still defined Protestants as heretics . Thus, Hilaire Belloc--in his time one of the most conspicuous speakers for Catholicism in Britain--was outspoken about the "Protestant Heresy". He even defined Islam as being "A Christian heresy", on the grounds that Muslims accept many of the tenets of Christianity but deny the godhood of Jesus (see Hilaire Belloc #On Islam). </P> <P> However, in the second half of the century--and especially in the wake of Vatican II--the Catholic Church, in the spirit of ecumenism, tends not to refer to Protestantism as a heresy nowadays, even if the teachings of Protestantism are indeed heretical from a Catholic perspective . Modern usage favors referring to Protestants as "separated brethren" rather than "heretics", although the latter is still on occasion used vis - a-vis Catholics who abandon their church to join a Protestant denomination . Many Catholics consider Protestantism to be material rather than formal heresy, and thus non-culpable . </P> <P> Some of the doctrines of Protestantism that the Catholic Church considers heretical are the belief that the Bible is the only source and rule of faith ("sola scriptura"), that faith alone can lead to salvation ("sola fide") and that there is no sacramental, ministerial priesthood attained by ordination, but only a universal priesthood of all believers . </P> <P> Postmodern Christianity is an understanding of Christianity that is closely associated with the body of writings known as postmodern philosophy . Although it is a relatively recent development in the Christian religion, many Christian postmodernists are quick to assert that their style of thought has an affinity with foundational Christian thinkers such as Augustine of Hippo and Thomas Aquinas and famed Christian mystics such as Meister Eckhart and Angelus Silesius . </P>

Christianity had no unified theology for its first three centuries because of