Christianity and Islam are the two main religions practiced in Nigeria[2][3] The country is home to some of the world's largest Christian and Muslim populations, simultaneously.[4] Reliable recent statistics do not exist; however, Nigeria is divided roughly in half between Muslims, who live mostly in the northern region, and Christians, who live mostly in the southern region of the country. Indigenous religions, such as those native to the Igbo and Yoruba ethnicities, have been declining for decades and being replaced by Christianity or Islam. The Christian share of Nigeria's population is also now on the decline, due to a lower fertility rate relative to the Muslim population in the country.[5]
Most Christians are Protestant (broadly defined), though about a quarter are Catholic.[6][7] The majority of Nigerian Muslims are either Sunni or non-denominational Muslims. Many Sunni Muslims are members of Sufi brotherhoods or Tariqa. Most Sufis follow the Qadiriyya, Tijaniyyah or Mouride movement. A significant Shia minority also exists (see Shia in Nigeria). There are also Ahmadiyya and Mahdiyya minorities. [8] In terms of Nigeria's major ethnic groups' religious affiliations, the Hausa ethnic group in the north is almost entirely Muslim,[9] and the Yoruba are religiously diverse, with most following either Christianity or Islam, though a significant number practice the Yoruba religion.[10][11][12] The Igbos of the east and the Ijaw in the south are almost entirely Christians with a few practitioners of traditional religions.[11] The Middle Belt of Nigeria contains most of the minority ethnic groups in Nigeria and they are mostly Christians and Christian converts, as well as members of traditional religions with few Muslim converts.[13][14]
Nigeria is officially a secular state with no official state religion. Article 10 of the Constitution states that “The Government of the Federation or a State shall not adopt any religion as State Religion.”[15] However, twelve Muslim-majority northern states have incorporated Sharia courts into their legal systems with the power and jurisdiction of these courts waxing and waning over the past two decades.[16] In some of these states, sharia courts are optional arbitration courts for personal status issues whereas, in others, Sharia has effectively replaced the formerly secular state level legal system in both civil and criminal contexts. This has brought controversy due to its discriminatory practices towards religious and sexual minorities.[17][18][19] Northern Nigeria has also been the site of ongoing Islamist insurgency which has led to the death and displacement of tens of thousands of people.[20]