Bangladesh followed by 86.6 percent of the population. The country is home to most Bengali Muslims, the second-largest ethnic group in the Muslim world. Most Bangladeshi Muslims are Sunni, followed by Shia and Ahmadiya. About four percent are non-denominational Muslims. Bangladesh has the fourth-largest Muslim population in the world, and is the third-largest Muslim-majority country (after Indonesia and Pakistan). Sufism has a lengthy heritage in the region. The largest gathering of Muslims in Bangladesh is the Bishwa Ijtema, held annually by the Tablighi Jamaat. The Ijtema is the second-largest Muslim congregation in the world, after the Hajj. Hinduism is followed by
Muslim world according to the Sunnah should be selected based on ٍShura (consultation), as was done at the Saqifah which selected Abu Bakr, Muhammad's father-in-law, to be Muhammad's political but not his religious successor. Shia, on the other hand, believe that Muhammad designated his son-in-law Ali ibn Abi Talib as his true political as well as religious successor. The overwhelming majority of Muslims in the world, between 87–90%, are Sunni. Shias and other groups make up the rest, about 10–13% of overall Muslim population. The countries with the highest concentration of Shia populations are: Iran – 96%, Azerbaijan – 85%, Iraq –