Roman Catholics, Anglicans, Eastern Christians, and traditional Protestant groups center their worship around a liturgical calendar. Some events that are part of this calendar are the "holy days", such as solemnities which honor an event in the life of Jesus or the saints, times of fasting such as Lent, and other events, such as memoria. Christian groups that do not follow a liturgical tradition often keep some celebrations, such as Christmas, Easter,and Pentecost. A few churches do not use a liturgical calendar.
These are some symbols that some denominations or individual churches may use:
Christianity has had a large history from the time of Jesus and his apostles to the present time. Christianity began in the 1st century AD as a Jewish sect but quickly spread throughout the Greco-Roman world. Although it was originally persecuted under the Roman Empire, it later became the state religion. In the Middle Ages it spread into Northern Europe and Russia. During the Age of Exploration, Christianity expanded throughout the world, and is now the largest religion of the world.
The religion had schisms and theological disputes that had as result ten main branches or groupings: Catholicism, Eastern Orthodoxy, the Church of the East (Nestorianism), Oriental Orthodoxy (Miaphysitism), Lutheranism, the Reformed churches (Calvinism), Anglicanism, Anabaptism, Evangelicalism—these last five often grouped and labeled as Protestant—and Nontrinitarianism.
People who call themselves Christians may show or live their faith in different ways. They may also believe different things. Through history the ten main groups or "denominations" of Christianity have been the (Eastern) Orthodox, the Church of the East (Nestorian), the Oriental Orthodox (Miaphysite), the Catholic, the Anglican, the Lutheran, the Reformed, the Anabaptist, the Evangelical, and the Nontrinitarian churches. These latter six are often grouped together as Protestant, but Nontrinitarians are also more commonly grouped separately. Not all Christians use these titles. Some believe Christianity is bigger and includes others. Some believe Christianity is smaller and does not include all these churches.
Some of these groups could not agree on certain points about Christian teaching (called “doctrine”) or practice. The first split was in the 5th century after the Church Council of Ephesus. The council agreed Nestorianism was wrong. The Assyrian Church of the East did not agree and split from the rest. The argument was about the nature of Jesus. Should he be regarded as God and human in one combined nature, or in two separate natures? Most of the bishops, following the Pope (the Bishop of Rome), refused to stay in communion with any bishop who would not say "two separate natures". This was also discussed at the Council of Chalcedon, about 20 years later. The Christians who did not agree with the decision of the Council to excommunicate them, became the non-Chalcedonian Orthodox. The largest Non-Chalcedonian Churches are the Coptic Orthodox in Egypt, the Ethiopian Orthodox, the Armenian, and some Lebanese Orthodox Churches. In general, these churches are known as Oriental Orthodox Churches. Recent discussions between the Roman Catholic Pope John Paul II and the Coptic Orthodox Pope Shenouda III concluded that they believe many of the same things after all, even though the Coptic Church does not recognize the Pope of Rome as its leader.
The third split happened in the 11th century. It is called the Great Schism. It was mostly based on the creed being translated incorrectly from Greek into Latin. The disagreements were made worse because the two cultures often did not understand one another. Also, many Crusaders from Western Europe behaved badly. The Christians in Western Europe were led by the Bishop of Rome, known also as the Pope. They are called the Catholic Church. Most Christians in Eastern Europe, Russia, the Middle East and South Asia, and northeast Africa belong to Orthodox, Nestorian, and Miaphysite Christianity, led by the Bishops of other cities or areas.
In the 15th century the invention of the printing press made it easier for more people to read and study the Bible. This led many thinkers over the years to return to biblical ideas and to break away from the Catholic Church. They started the Protestant Reformation. The most important Protestant leaders were Jan Hus, Martin Luther, and John Calvin. Later some of these groups disagreed amongst themselves so that these denominations split again into smaller groups. The largest Protestant denominations today are within Evangelical, Lutheran, and Reformed Christianity. In England, a similar protest against the Pope, first political and later religious, led to the Church of England which has bishops and officially calls itself Reformed Catholic but is often referred to as Protestant. The Anglican communion of churches includes several churches called "Episcopal" or "Episcopalian" because they have bishops. Some Anglican Churches have a style of worship that is closer to the Protestant services, others worship more like Catholics, but none of them accept the Pope, or are accepted by him. The Anabaptists also arose from disagreements with Lutheran and Reformed Protestants during what is often called the Radical Reformation. The Evangelical churches arose in reaction to what they views as needs for reform within mainstream Protestantism. This can be seen in the rise of non-conformist movements against the Anglican church in Britain and during revivalist movements, prominently in the several Great Awakenings in Britain and North America. Denominations that arose or surged as a result of these Evangelical reform, renewal, and revival movements include Quakers, Baptists, Moravians, Methodists, the Restoration (Stone-Campbell) movement, Adventists, the Holiness movement, Pentecostals, the Fundamentalist movement, the Charismatic movement, Messianic Judaism, among others including many independent and non-denominational churches. In general, some Protestant denominations, especially within Anabaptism and Evangelicalism, differ from the Catholic, Orthodox, Nestorian, and Miaphysite churches in having given up some of the traditional sacraments, having no ordained priesthood, and not having the same fondness for Mary, the mother of Jesus, that the Catholic and Eastern churches have.
With an estimated number of Christians being somewhere around 2.2 billion, split into around 34,000 different denominations, Christianity is the world's largest religion. The Christian share of the world's population has been around 33% for the last hundred years. This has caused Christianity to spread throughout the world, mainly in Europe and North America. It is still the main religion of Europe, the Americas, the Philippines, and Southern Africa. However it is becoming smaller in some areas, some of them are; Oceania (Australia and New Zealand), Northern Europe (with Great Britain, Scandinavia and other places), France, Germany, the Canadian provinces of Ontario, British Columbia, and Quebec, the Western and Northern parts of the United States, and parts of Asia (especially the Middle East, South Korea, Taiwan and Macau).
In most countries in the developed world, the number of people going to church who claim to be Christians has been dropping over the last few decades. Some believe that this is only because many no longer use regular membership in places, for example, churches, while others believe it is because people may be thinking that religion is no longer important.