▁particular ▁culture . ▁Christian ity , ▁Islam , ▁Buddh ism ▁and ▁J ain ism ▁are ▁universal ▁relig ions ▁while ▁H indu ism ▁and ▁J uda ism ▁are ▁eth nic ▁relig ions . ▁ ▁Dem ographical ▁classification ▁ ▁The ▁five ▁largest ▁religious ▁groups ▁by ▁world ▁population , ▁estimated ▁to ▁account ▁for ▁ 5 . 8 ▁billion ▁people ▁and ▁ 8 4 % ▁of ▁the ▁population , ▁are ▁Christian ity , ▁Islam , ▁Buddh ism , ▁H indu ism ▁( with ▁the ▁relative ▁numbers ▁for ▁Buddh ism ▁and ▁H indu ism ▁dependent ▁on ▁the ▁extent ▁of ▁syn cret ism ) ▁and ▁traditional ▁folk ▁religion . ▁ ▁A ▁global ▁poll ▁in ▁ 2 0 1 2 ▁survey ed ▁ 5 7 ▁countries ▁and ▁reported ▁that ▁ 5 9 % ▁of ▁the ▁world ' s ▁population ▁identified ▁as ▁religious , ▁ 2 3 % ▁as ▁not ▁religious , ▁ 1 3 % ▁as ▁convinced ▁at he ists , ▁and ▁also ▁a ▁ 9 % ▁decrease ▁in ▁identification ▁as ▁religious ▁when ▁compared ▁to ▁the ▁ 2 0 0 5 ▁average ▁from ▁ 3 9 ▁countries . ▁A ▁follow - up ▁poll ▁in ▁ 2 0 1 5 ▁found ▁that ▁ 6 3 % ▁of ▁the ▁glo be ▁identified ▁as ▁religious , ▁ 2 2 % ▁as ▁not ▁religious , ▁and ▁ 1 1 % ▁as ▁convinced ▁at he ists . ▁On ▁average , ▁women ▁are ▁more ▁religious ▁than ▁men . ▁Some ▁people ▁follow ▁multiple ▁relig ions ▁or ▁multiple ▁religious ▁principles ▁at ▁the ▁same ▁time , ▁regardless ▁of ▁whether