What two Christian religion is common in eastern European?

The two most common Christian religions in Eastern Europe are Eastern Orthodox Christianity and Roman Catholicism.

Eastern Orthodox Christianity is the dominant religion in Russia, Ukraine, Belarus, Moldova, Serbia, Bulgaria, Romania, and Greece. It is also practiced by significant minorities in other countries in the region, such as Poland, Hungary, the Czech Republic, and Slovakia. Eastern Orthodox Christianity is based on the teachings of the early Church Fathers and the decisions of the seven Ecumenical Councils. It emphasizes the importance of tradition and the sacraments, and it places a strong emphasis on the veneration of saints.

Roman Catholicism is the dominant religion in Poland, Hungary, the Czech Republic, Slovakia, Slovenia, Croatia, Bosnia and Herzegovina, and Montenegro. It is also practiced by significant minorities in other countries in the region, such as Romania, Bulgaria, and Serbia. Roman Catholicism is based on the teachings of the Roman Catholic Church, which is led by the Pope. It emphasizes the importance of the papacy and the sacraments, and it places a strong emphasis on the authority of the Church.