Due to the problems that Christians currently have with Islam, I did a little research on quantities.
Christianity makes up approximately 0ne quarter to one third of those professing religion. About 2 billion.
Islam is about half that many. 1 billion.

The rest of the major religions are made up of approximately the following: (there are thousands of non-major ones)

Hinduism 1 bil.; Folk Religions 1/2 bil., Buddhism 1/2 bil.; Chinese Folk 1/2 bil.; Shinto 3 million; Sikhism 24 million; Judaism 14 million; Bahai 8 million;
Jainism 6 million; Cheonaoism 3 million; Tenrikto 3 million; Tenrikyo 2 million; Caodai 2 million; Wicca 1 million; Sekai Kyuseilyo 1 million; Seicho-nu.le 1 million; Rastafarian 1 million; Unitarian Universalistic 1 million.

With the exception of Christianity, and Islam and Hinduism, I think the other religions have little if anything to do with governing their countries.

When religion gets mixed up with government leadership then ALL of that religion is blamed for what the government does!