Germany is roughly evenly split between Catholic and Protestant Christian heritage, though both have declined sharply in recent decades to around 24 to 26 percent each, with religiously unaffiliated Germans now forming the largest single group at over a third of the population, alongside a Muslim minority near 5 to 6 percent, chiefly of Turkish descent from postwar labor migration, per estimates including Pew Research's Religious Composition of the World, 2010-2020.
Germany was the birthplace of the Protestant Reformation, launched when Martin Luther posted his Ninety-Five Theses in Wittenberg in 1517, challenging Catholic Church practices including the sale of indulgences and igniting a religious schism that fractured the Holy Roman Empire along confessional lines for over a century, formalized in the 1555 Peace of Augsburg's principle that a ruler's religion determined that of his territory.
The Thirty Years' War of 1618 to 1648, fought substantially along Catholic-Protestant lines though entangled with wider European power politics, devastated Central Europe before the 1648 Peace of Westphalia established a lasting framework for religious coexistence. Germany's Jewish community, a major center of European Jewish culture and Reform Judaism's birthplace in the nineteenth century, was almost entirely destroyed by the Holocaust, and today's much smaller Jewish population is partly rebuilt through postwar immigration, notably from the former Soviet Union.