Persecution of Christians in the context of "Heresy in Christianity"

Christianity in Turkey has a long history, dating back to the early origins of Christianity in Asia Minor and the Middle East during the 1st century AD. In modern times the percentage of Christians in Turkey has declined from 20 to 25% in 1914, to about 2% in 1927, to 0.2–0.4% today. Sources estimate that the Christian population in Turkey ranges between 203,500 and more than 370,000. However, the exact number remains unclear due to the absence of a religious census in the country. The percentage of Christians in Turkey fell mainly as a result of the late Ottoman genocides: the Armenian genocide, Greek genocide, and Assyrian genocide, the population exchange between Greece and Turkey, the emigration of Christians that began in the late 19th century and gained pace in the first quarter of the 20th century, and due to events such as the 1942 Varlık Vergisi tax levied on non-Muslim citizens in Turkey and the 1955 Istanbul pogrom against Greek and Armenian Christians. Exact numbers are difficult to estimate, as many Turkish former Muslim converts to Christianity often hide their Christian faith for fear of familial pressure, religious discrimination, and persecution.

This was due to events which had a significant impact on the country's demographic structure, such as the First World War, the anti-Christian genocides of Greeks, Armenians, and Assyrians perpetrated by Turkish Muslims, and the population exchange between Greece and Turkey, and the emigration of persecuted Christians (such as Assyrians, Greeks, Armenians, etc.) to foreign countries (mostly in Europe and the Americas) that began in the late 19th century and gained pace in the first quarter of the 20th century, especially during World War I. Signed after the First World War, the Treaty of Lausanne explicitly guarantees the security and protection of both Greek and Armenian Orthodox Christian minorities. Their religious institutions are recognized officially by the Republic of Turkey.

A Christian (/ˈkrɪstʃən, -tiən/ ) is a person who follows or adheres to Christianity, a monotheistic Abrahamic religion based on the life and teachings of Jesus Christ. Christians form the largest religious community in the world. The words Christ and Christian derive from the Koine Greek title Christós (Χριστός), a translation of the Biblical Hebrew term mashiach (מָשִׁיחַ) (usually rendered as messiah in English). While there are diverse interpretations of Christianity which sometimes conflict, they are united in believing that Jesus has a unique significance. The term Christian used as an adjective is descriptive of anything associated with Christianity or Christian churches, or in a proverbial sense "all that is noble, and good, and Christ-like."

According to a 2011 Pew Research Center survey, there were 2.3 billion Christians around the world, up from about 600 million in 1910. Today, about 37% of all Christians live in the Americas, about 26% live in Europe, 24% live in sub-Saharan Africa, about 13% live in Asia and the Pacific, and 1% live in the Middle East and North Africa. Christians make up the majority of the population in 158 countries and territories. 280 million Christians live as a minority. About half of all Christians worldwide are Catholic, while more than a third are Protestant (37%). Eastern Christians, including the Eastern Orthodox, Oriental Orthodox, and Church of the East, comprise 12% of the world's Christians. Other Christian groups make up the remainder. By 2050, the Christian population is expected to exceed 3 billion due to overall total fertility rate according to Pew Research Center. According to a 2012 Pew Research Center survey, Christianity will remain the world's largest religion in 2050, if current trends continue. In recent history, Christians have experienced persecution of varying severity, especially in the Middle-East, North Africa, East Asia, and South Asia.

Christianity, which originated in the Middle East during the 1st century AD, is a significant minority religion within the region, characterized by the diversity of its beliefs and traditions, compared to Christianity in other parts of the Old World. Today, Christians make up approximately 5% of the Middle Eastern population, down from 13-20% in the early 20th century. Cyprus is the only Christian majority country in the Middle East, with Christians forming between 76% and 78% of the country's total population, most of them adhering to Eastern Orthodox Christianity. Lebanon has the second highest proportion of Christians in the Middle East, around 40%, predominantly Maronites. After Lebanon, Egypt has the next largest proportion of Christians (predominantly Copts), at around 10% of its total population. Copts of Egypt, numbering around 10 million, constitute the single largest Christian community in the entire Middle East.

The Eastern Aramaic speaking Assyrians of northern Iraq, northeastern Syria, southeastern Turkey, and parts of Iran have suffered due to ethnic cleansing, religious discrimination, and persecution for many centuries. During the 20th century, the percentage of Christians in the Middle East fell mainly as a result of the late Ottoman genocides: the Armenian genocide, Greek genocide, and Assyrian genocide committed against them by the Ottoman Turks and their allies, leading many to flee and congregate in areas in northern Iraq, northeastern Syria, North America, and Western Europe. The great majority of Aramaic speaking Christians are followers of the Assyrian Church of the East, Chaldean Catholic Church, Syriac Orthodox Church, Ancient Church of the East, Assyrian Pentecostal Church and Assyrian Evangelical Church. In Iraq, the numbers of Christians has declined to between 300,000 and 500,000 (from 0.8 to 1.4 million before 2003 US invasion). Assyrian Christians were between 800,000 and 1.2 million before 2003. In 2014, the population of the Nineveh Plains in northern Iraq was scattered to Dohuk, Erbil and Jordan due to ISIS forcing the Assyrian community out of their historical homeland, but since the defeat of the Islamic State in 2017, Christians have slowly began returning.

The late Ottoman genocides is a historiographical theory which sees the concurrent Armenian, Greek, and Assyrian genocides that occurred during the 1910s–1920s as parts of a single event rather than separate events, which were initiated by the Young Turks. Although some sources, including The Thirty-Year Genocide (2019) written by the historians Benny Morris and Dror Ze'evi, characterize this event as a genocide of Christians, others such as those written by the historians Dominik J. Schaller and Jürgen Zimmerer contend that such an approach "ignores the Young Turks' massive violence against non-Christians", in particular against Muslim Kurds.

Anti-Christian sentiment, also referred to as Christianophobia or Christophobia, is the fear, hatred, discrimination, or prejudice against Christians and/or aspects of the Christian religion's practices. These terms encompass "every form of discrimination and intolerance against Christians". The presence of anti-Christian sentiment has frequently led to the persecution of Christians throughout history.

In the canon law of the Catholic Church, a mission sui iuris (Latin: missio sui iuris, pl. missiones sui iuris), also known as an independent mission, can be defined as: "an ecclesial structure erected from a previous territory, with explicit boundaries, under the care of a religious community or other diocese, responding to a missionary exigency and headed by a superior nominated by the Holy See, under the aegis of the Congregation for the Evangelization of Peoples."

It is generally applied to an area with very few Catholics, or in areas where Christianity (in particular Roman Catholicism) is either outlawed or undergoing persecution, often desolate or remote, and ranks below an apostolic prefecture and an apostolic vicariate.

The Saint Thomas Christians, also called Syrian Christians of India, Marthoma Suriyani Nasrani, Malankara Nasrani, or Nasrani Mappila, are an ethno-religious community of Indian Christians in the state of Kerala (Malabar region), who, for the most part, employ the Eastern and Western liturgical rites of Syriac Christianity. They trace their origins to the evangelistic activity of Thomas the Apostle in the 1st century. The Saint Thomas Christians had been historically a part of the hierarchy of the Church of the East but are now divided into several different Eastern Catholic, Oriental Orthodox, Protestant, and independent bodies, each with their own liturgies and traditions. They are based in Kerala and they speak Malayalam. Nasrani or Nazarene is a Syriac term for Christians, who were among the first converts to Christianity in the Near East.

Historically, this community was organised as the Province of India of the Church of the East, by Patriarch Timothy I (780–823 AD) in the eighth century, it was served by bishops and a local dynastic archdeacon. In the 14th century, the Church of the East declined in the Near East, due to persecution from Tamerlane. Portuguese colonial overtures to bring St Thomas Christians into the Latin Church of the Catholic Church, administered by their Padroado system in the 16th century, led to the first of several rifts (schisms) in the community. The attempts of the Portuguese culminated in the Synod of Diamper, formally subjugating them to the Portuguese Padroado and imposing upon them the Roman Rite of worship. The Portuguese oppression provoked a violent resistance among the Thomasine Christians, that took expression in the Coonan Cross Oath protest in 1653. This led to the permanent schism among the Thomas' Christians of India, leading to the formation of Puthankoor or Puthankūttukār ("New allegiance" ) and Paḻayakūṟ or Pazhayakūr ("Old allegiance") factions. The Paḻayakūṟ comprise the present day Syro-Malabar Church and Chaldean Syrian Church which continue to employ the original East Syriac Rite. The Puthankoottukar, who continued to resist the Catholic missionaries, organized themselves as the independent Malankara Church and entered into a new communion with the Syriac Orthodox Church of Antioch, inheriting from them the West Syriac Rite, replacing the old East Syriac Rite liturgy.