Missionaries: These are individuals who leave their homes to spread a religious message or convert others to their faith. In this case, Christian missionaries played a significant role in spreading Christianity.
Colonization: This is when one country takes control over another area with the intent to establish settlements and exploit resources. Colonization often involved spreading religion as well, including Christianity.
Cultural Diffusion: This is the spread of cultural beliefs and social activities from one group to another. The mixing of world cultures through different ethnicities, religions, and nationalities has increased with advanced communication, transportation, and technology.