Why do you think Christianity did not gain many followers in Africa or most of Asia?
1 Answer
In it's first centuries, Christianity gained many adherents in Africa and Asia, but the barriers to travel in that era checked much of its spread.
Explanation:
By 600 AD, Christianity has spread through much of Europe, North Africa and the Middle East. It was making inroads into Ethiopia, but it was seen as a 'Roman' religion in Sasanian Persia which inhibited its growth to the east. A new generation of missionaries in Western Europe were spreading the word among various German peoples and starting to move beyond them.
Nestorian Christians were also spreading through Asia along caravan and shipping routes and would reach India and China -- to form small communities. However, trade in this time was tenuous. The Sahara and the disease barriers on the far side of it long inhibited European and Asian access to sub-Saharan Africa for centuries to come. Full access to Africa only came in the 19th Century.
The eruption of Islam and its coercive spread limited Christianity in Northern Africa and much of the Middle East. Christians, Jews and Zoarastrians were offered Dhimmi status (restrictive rights as second class citizens -- with many limitations on the practice of their religion). Regardless, Christian communities still linger, often having suffered many centuries of persecution.
Christianity is an attractive religion that offers many benefits in terms of answers to human needs, social stability and cohesion. The same is also true of Buddhism and Hinduism; which were more native to Asia and Asian cultural preferences.
Islam does not allow competetion, where Buddhism and Hinduism are more robust in expression and human fulfillment. Once past the barriers presented by Islamic cultures, Christian missionaries had a harder time gaining converts in Asia.