Eastern Orthodoxy by country
The number of members of the Eastern Orthodox Church in each country has been subject to a lot of debate. Each study performed that seeks to discover the number of adherents in a country may use different criteria, and be submitted to different populations. As such, some numbers may be inflated, and therefore inaccurate. Examples of this are Greece and Russia, where estimates of adherence to Eastern Orthodoxy may reach 80-98%, but where surveys found lower percentages professing Eastern Orthodoxy or belief in God. The likely reason for this disparity is that many people in these majority Eastern Orthodox countries will culturally identify with the Eastern Orthodox Church, especially if they were baptized as children, even if they are not currently practicing. This includes those who may be irreligious, yet culturally identify with the Eastern Orthodox Church, or for whom Eastern Orthodox Christianity is listed on official state records. Other cases of incongruent data also might be due to counting ethnic groups from Eastern Orthodox countries rather than actual adherents. A case of this is the United States, which has large numbers of immigrants from Eastern Orthodox countries. The Eastern Orthodox jurisdictions often reported large numbers of members, which together would total 2-3 million across the country. However, a 2010 study by Alexei Krindatch sought data from each parish, with the specific criteria of annual participation. This study produced the "Atlas of American Orthodox Christian Churches", and discovered that there were only about 817,000 Eastern Orthodox Christians actively practicing their faith (that is to say, attending church services on a regular basis) in the United States. The study explained that such a difference was due to a variety of circumstances, for example the higher numbers having counted all people who self-identify as Eastern Orthodox on a census regardless of active participation, or all people belonging to ethnic groups originating in Eastern Orthodox countries. This study, while initially controversial, proved groundbreaking, and has since been officially approved for use by the Assembly of Canonical Orthodox Bishops of the United States of America.
Apostasy in Islam
Muslims constitute approximately 36.5–37% to 48–50% of the Eritrean population; more than 99% of Eritrean Muslims are Sunnis. Although there are no legal restrictions on leaving Sunni Islam, there are only three other officially recognised religions in Eritrea, all of them Christian: the Eritrean Orthodox Tewahedo Church, the Eritrean Catholic Church (in full communion with the Roman Catholic Church) and the Evangelical Lutheran Church of Eritrea. Despite other religious groups applying for original recognition since 2002, the Eritrean government has failed to implement the relevant rights established in the constitution. It is illegal or unrecognised to identify as an atheist or as non-religious, and illegal to register an explicitly humanist, atheist, secularist or other non-religious NGO or other human rights organisation, or such groups are persecuted by authorities. Members of “unrecognised” religions are arrested, detained in oppressive conditions, and there have been reports that people have been tortured in order for them to recant their religious affiliation. Reports of the harassment and arrest of members of religious minority groups is widespread and frequent. Open Doors reported that Muslims who become Christians in Muslim-majority areas are frequently rejected, mistreated or even disowned by their families. Additionally, the Orthodox Church considers itself the only true Christian denomination in the country and puts its ex-members who convert to a Protestant faith under pressure to return.