Within a few hundred years, the small, often hated Christianity became the most important religion of Europe and the Western world. By becoming the state religion of the Roman Empire, Christianity became the largest and strongest religion in the world.
Christianity was spread through the Roman Empire by the early followers of Jesus. Even though saints Peter and Paul are said to have established the church in Rome, most of the early Christian communities were in the east like Alexandria in Egypt, as well as Antioch and Jerusalem. Christianity gained followers among both Jewish and non-Jewish, bringing them together with a message of unity before God.
Constantine legalized and sponsored Christianity