Switzerland has no official state religion, though most of the cantons (except Geneva and Neuchâtel) recognize official churches, in all cases including the Catholic Church and the Swiss Reformed Church. These churches, and in some cantons also the Old Catholic Church and Jewish congregations, are financed by official taxation of adherents.Christianity is the predominant religion of Switzerland, divided between the Catholic Church (41.8% of the population) and various Protestant denominations (35.3%). Immigration has brought Islam (4.3%, predominantly Kosovars) and Eastern Orthodoxy (1.8%) as sizeable minority religions. The 2005 Eurobarometer poll found 48% to be theist, 39% expressing belief in "a spirit or life force", 9% atheist and 4% agnostic.
The country is historically about evenly balanced between Catholic and Protestant, with a complex patchwork of majorities over most of the country. One canton, Appenzell, was officially divided into Catholic and Protestant sections in 1597. The larger cities (Bern, Zürich and Basel) are predominantly Protestant. Central Switzerland, as well as the Ticino, is traditionally Catholic. The Swiss Constitution of 1848, under the recent impression of the clashes of Catholic vs. Protestant cantons that culminated in the Sonderbundskrieg, consciously defines a consociational state, allowing the peaceful co-existence of Catholics and Protestants. A 1980 initiative calling for the complete separation of church and state was resoundingly rejected, with only 21.1% voting in support.