Although Islam began in the middle east, there are far more Muslims in Asian countries, specifically Iraq, Iran, Pakistan, India and Indonesia. Indonesia is very close to 100% Muslim and has a high population which accounts for it coming in at number one.

Before Islam arrived, the primary religions in Indonesia were Buddhism and Hinduism.

There are many different theories as to how Islam spread to Indonesia. One theory holds that Islam spread directly to Indonesia in the 9th century. Others believe that Islam came to Indonesia in the 12th and 13th centuries via Sufi merchants from India and Pakistan.

Sufism is a type of Islamic mysticism, more concentrated on the inward dimension of Islam, its rituals, values, doctrines and institutions.

We do know the spread of Islam accelerated greatly in the 15th century with the Melaka Sultanate and other Islamic sultanates dominating the region. These sultanates required their subject to convert. Unlike other areas in the South Pacific, Christianity never gained a foothold in Indonesia. It is interesting to note how Islam took over in Indonesia as opposed to India, where multiple religions have strong footholds.

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