Poland has been one of the world's most strongly Roman Catholic countries. During the period of Communist domination that began in 1945, that church suffered extensive repression by the state. A change in party leadership in October 1956, however, brought about a new relationship between church and state, which included voluntary religious instruction in schools and other guarantees to the Roman Catholic Church. In 1974, the Polish government established permanent working contacts with the Holy See. The position of the Church was further enhanced when the archbishop of Cracow, Karol Cardinal Wojtyla, became Pope John Paul II in 1978. Three visits by the pope to Poland, 2– 10 June 1979, 16–23 June 1983, and 8–14 June 1987, testified to the strength of Polish Catholicism. In 1989, the church was finally granted legal status and control of its schools, hospitals, and its university in Lublin.
It is estimated that over 96% of Poles are nominally Roman Catholics. However, a 2001 poll indicates that only 58% of the entire population are active practitioners of their chosen faith. About 509,500 people are registered members of the Orthodox Church, 123,000 are Greek Catholics, 122,757 are Jehovah's Witnesses, and 87,300 are Lutherans (Augsburg). Other established Christian denominations include Old Catholic Mariavits, Polish-Catholics, Pentecostals, Seventh-Day Adventists, Baptists, Methodists, the Church of Christ, Reformed Lutherans,
and the New Apostolic Church. The Muslim Religious Union has about 5,123 members. About 5,043 people are Hare Krishnas.
On the eve of World War II, an estimated 3,351,000 Jews lived in Poland, more than in any other country; they constituted about 10% of the Polish population and nearly 20% of world Jewry. During the course of the Nazi occupation (1939–45), nearly 3,000,000 Polish Jews were killed, many of them in extermination camps such as Auschwitz (Os ´wiecim), near Cracow. Most of the survivors had fled to the USSR; at the end of the war, only about 55,000 Jews remained in Poland. Repatriation raised the total Jewish population to 250,000 in 1946. However, the establishment of the State of Israel in 1948, combined with a series of anti-Semitic outbreaks in Poland (including a government-led campaign in 1968–69), induced most Jews to emigrate. By 1998, Poland had only about 10,000 to 30,000 Jews living in the country.