Christianity became the main and eventually only religion of the Roman, then the British, Spanish and French Empires. Because of the controlling ways of each the religion was forced upon the people of the conquered areas. Agreed that these Christian conversions were not generally done on a voluntary basis, but their descendants have remained Christian after gaining their independence from the European countries, and Christian missionaries are still active in the world today.
More than likely, God had a lot to do with it.
the emigration of Christians to non-Christian areas around the world
Christianity has long been geographically widespread.This is mostly due to missionaries who travel the world to spread the "Good News."
Roman Catholicism
The most widespread religion is Christianity.
The most widespread religion on earth is Christianity, followed closely by the Baha'i Faith.
The two main ones were Mithraism and Christianity.
Christianity appealed to people because it has the answers to the important questions in life. eg Why are we here? What happens to us after death?
It teaches love, peace, and respect for your fellow human being.
Catholicism is, & it also happens to be the oldest form too.
With around 2.4 billion adherents split into three main branches of Catholic, Protestant and Eastern Orthodox, Christianity is the world's largest religion
Catholic Christianity is very widespread along side the Indigenous Traditional Religions