Christianity in the 20th century was characterized by an accelerating secularization of Western society, which had begun in the 19th century, and by the spread of Christianity to non-Western regions of the world.
Christian ecumenism grew in importance, beginning at the Edinburgh Missionary Conference in 1910, and accelerated after the Second Vatican Council of the Catholic Church, The Liturgical Movement became significant in both Catholic and Protestant Christianity, especially in Anglicanism.
At the same time, state-promoted atheism in communist Eastern Europe and the Soviet Union brought persecution to many Eastern Orthodox and other Christians. Many Orthodox came to Western Europe and the Americas, leading to greatly increased contact between Western and Eastern Christianity. Nevertheless, church attendance declined more in Western Europe than it did in the East. (Christianity) The Roman Catholic Church instituted many reforms in order to modernize. Catholic and Protestant missionaries also made inroads in the Far East, establishing further followings in mainland China, Taiwan, and Japan.