Catholicism is, & it also happens to be the oldest form too.
Roman Catholicism
The most widespread religion on earth is Christianity, followed closely by the Baha'i Faith.
The most widespread religion is Christianity.
the emigration of Christians to non-Christian areas around the world
A poll stated that 'Africe' has the most Christians - approximately 340 million. See related link for countries with Christian population data:
The two main ones were Mithraism and Christianity.
Christianity has long been geographically widespread.This is mostly due to missionaries who travel the world to spread the "Good News."
With around 2.4 billion adherents split into three main branches of Catholic, Protestant and Eastern Orthodox, Christianity is the world's largest religion
More than likely, God had a lot to do with it.
Islam is the most widespread religion in the world.
Comman bermudagrass is one of the most widespread horticultures.
Edward Gibbon (The Decline and Fall of the Roman Empire) says that by the early part of the fourth century, Christianity was strongest in the eastern Empire and in the province of Africa (based on Carthage), as well as in Rome itself. He says that Christianity continued to struggle for converts in Gaul and Britain, and that outside Alexandria, the Egyptians showed little interest in Christianity.