Religion in Russia is diverse, with Orthodox Christianity being the most widely professed faith, but with significant minorities of non-religious people and adherents of other faiths. A 1997 law on religion recognises the right to freedom of conscience and creed to all the citizenry, the spiritual contribution of Orthodox Christianity to the history of Russia, and respect to "Christianity, Islam, Buddhism, Judaism and other religions and creeds which constitute an inseparable part of the historical heritage of Russia's peoples", including ethnic religions or paganism, either preserved, or revived. According to the law, any religious organisation may be recognised as "traditional", if it was already in existence before 1982, and each newly founded religious group has to provide its credentials and re-register yearly for fifteen years, and, in the meantime until eventual recognition, stay without rights.
As of the year 2021, Christianity had approximately 2.38 billion adherents and is the largest religion by population respectively. According to a PEW estimation in 2020, Christians made up to 2.38 billion of the worldwide population of about 8 billion people. It represents nearly one-third of the world's population and is the largest religion in the world, with the three largest groups of Christians being the Catholic Church, Protestantism, and the Eastern Orthodox Church. The largest Christian denomination is the Catholic Church, with 1.3 billion baptized members. The second largest Christian branch is either Protestantism, or the Eastern Orthodox Church.
The dominant religion in Vojvodina is Orthodox Christianity, mainly represented by the Serbian Orthodox Church, while other important religions of the region are Catholic Christianity, Protestant Christianity, Islam, and Judaism.
Religion has been a major influence on the societies, cultures, traditions, philosophies, artistic expressions and laws within present-day Europe. The largest religion in Europe is Christianity. However, irreligion and practical secularisation are also prominent in some countries. In Southeastern Europe, three countries have Muslim majorities, with Christianity being the second-largest religion in those countries. Ancient European religions included veneration for deities such as Zeus. Modern revival movements of these religions include Heathenism, Rodnovery, Romuva, Druidry, Wicca, and others. Smaller religions include Indian religions, Judaism, and some East Asian religions, which are found in their largest groups in Britain, France, and Kalmykia.
Serbia has been traditionally a Christian country since the Christianization of Serbs by Clement of Ohrid and Saint Naum in the 9th century. The dominant confession is Eastern Orthodoxy in the fold of Serbian Orthodox Church.
Eastern Orthodox Christianity is largest religion in Montenegro, but there are also sizeable numbers of adherents of both Catholic Christianity and Islam.
As of 2011, most Armenians in Armenia are Christians (97%) and are members of the Armenian Apostolic Church, which is one of the oldest Christian churches. It was founded in the 1st century AD, and in 301 AD became the first branch of Christianity to become a state religion.
Christianity in Azerbaijan is a minority religion. Christians who estimated between 280,000 and 450,000 (3.1%–4.8%) are mostly Russian and Georgian Orthodox. There is also a small Protestant Christian community which mostly came from Muslim backgrounds. Due to the very hostile relations between Azerbaijan and Armenia, Armenian Christians have practically entirely fled the country, and so the Christians in Azerbaijan are members of various other groups, mostly Russians.
Christianity is the main religion in Romania, with Romanian Orthodoxy being its largest denomination.
Christianity is the predominant religion in Ukraine, with 85% of the population identifying as Christian according to a 2022 survey conducted by the Kyiv International Institute of Sociology (KIIS). Seventy-two percent of the population avowed fidelity to an Eastern Orthodox Church: 54% of Ukrainians proclaimed adherence to the autocephalous Orthodox Church of Ukraine; 14% identified as Orthodox Christian without specifying a church affiliation; 4% associated with the Moscow Patriarchate. Another 9% of Ukrainians professed devotion to the Catholic Church in Ukraine: 8% Ukrainian Greek Catholics and 1% Latin Catholics. Two percent of the population declared affiliation to a mainstream Protestant Church, and a further 2% identified with some alternative sect of Christianity.
Christianity has dominated Guatemalan society since its Spanish colonial rule, but the nature of Christian practice in the country has changed in recent decades.
Christianity is the most prevalent religion in the United States. Estimates from 2021 suggest that of the entire U.S. population about 63% is Christian. The majority of Christian Americans are Protestant Christians, though there are also significant numbers of American Roman Catholics and other Christian denominations such as Latter-day Saints, Orthodox Christians and Oriental Orthodox Christians, and Jehovah's Witnesses. The United States has the largest Christian population in the world and, more specifically, the largest Protestant population in the world, with nearly 210 million Christians and, as of 2021, over 140 million people affiliated with Protestant churches, although other countries have higher percentages of Christians among their populations. The Public Religion Research Institute's "2020 Census of American Religion", carried out between 2014 and 2020, showed that 70% of Americans identified as Christian during this seven-year interval. In a 2020 survey by the Pew Research Center, 65% of adults in the United States identified themselves as Christians. They were 75% in 2015, 70.6% in 2014, 78% in 2012, 81.6% in 2001, and 85% in 1990. About 62% of those polled claim to be members of a church congregation.
Christianity is the main religion in Belarus, with Eastern Orthodoxy being the largest denomination. The legacy of the state atheism of the Soviet era is evident in the fact that a part of the Belarusians are not religious. Moreover, other non-traditional and new religions have sprung up in the country after the end of the Soviet Union.
In North Macedonia, the most common religion is Eastern Orthodox Christianity, practiced mainly by ethnic Macedonians, Serbians, Vlakhs, and Romanis. The vast majority of the Eastern Orthodox in the country belong to the Macedonian Orthodox Church, which declared autocephaly from the Serbian Orthodox Church in 1967.
Christianity is the most adhered-to religion in Canada, with 19,373,330 Canadians, or 53.3%, identifying themselves as of the 2021 census. The preamble to the Canadian Charter of Rights and Freedoms refers to God. The French colonization beginning in the 17th century established a Roman Catholic francophone population in New France, especially Acadia and Lower Canada. British colonization brought waves of Anglicans and other Protestants to Upper Canada, now Ontario. The Russian Empire spread Orthodox Christianity in a small extent to the tribes in the far north and western coasts, particularly hyperborean nomads like the Inuit. Orthodoxy would arrive in mainland Canada with immigrants from the eastern and southern Austro-Hungarian Empire and western Russian Empire starting in the 1890s; then refugees from the Soviet Union, Eastern Bloc, Greece and elsewhere during the last half of the 20th century.
Estonia, historically a Lutheran Christian nation, is today one of the "least religious" countries in the world in terms of declared attitudes, with only 14 percent of the population declaring religion to be an important part of their daily life. This is thought to largely be a result of the Soviet occupation of Estonia in 1940, prior to which Estonia had a large Christian majority.
A national church is a Christian church associated with a specific ethnic group or nation state. The idea was notably discussed during the 19th century, during the emergence of modern nationalism.
Christianity is the predominant religion in Serbia. The Constitution of Serbia defines it as a secular state with guaranteed religious freedom. Eastern Orthodox Christians with 6,079,396 members, comprise 84.5% of country's population. The Serbian Orthodox Church is the largest and traditional church of the country; adherents of it are overwhelmingly Serbs. Public schools in Serbia allow religious teaching, most commonly with the Serbian Orthodox Church. Serbian public holidays include the religious celebrations of Eastern Orthodox Christians. Other Orthodox Christian communities in Serbia include Montenegrins, Romanians, Macedonians, and Bulgarians. The Catholic Church is prominent in north Vojvodina amongst the Hungarian minority. Protestantism is most largely found in Slovak populations within Bački Petrovac and Kovačica. Christianity first arrived in Serbia in the 9th century. It became state-religion in the 9th century when Serbia began to identify as a Christian country. In a 2011 census, 91.22% of Serbians identified as Christian.
The Eastern Orthodoxy in Europe constitutes the second largest Christian denomination. European Eastern Orthodox Christians are predominantly present in Eastern and Southeastern Europe, and they are also significantly represented in diaspora throughout the Continent. The term Eastern Orthodox Europe is informally used to describe the predominantly Eastern Orthodox countries of Eastern Europe, as well as, Belarus, Bulgaria, Cyprus, Georgia, Greece, Moldova, Montenegro, North Macedonia, Romania, Russia, Serbia and Ukraine.
Oriental Orthodox Churches are the churches descended from those that rejected the Council of Chalcedon in 451. Despite the similar name, they are therefore a different branch of Christianity from the Eastern Orthodox. Oriental Orthodoxy consists of several autocephalous and autonomous jurisdictions holding a single set of beliefs and united in full communion. However, they each have their own separate rites, and there are significant differences between their respective practices. Thus, there is more internal diversity of practice among the Oriental Orthodox than among the Eastern Orthodox.
