Since most other nations around it are Buddhist/indigenous/Christian, I was wondering why and how Indonesia has a majority of the population following the Islamic Faith.
There is always more to say, certainly about such a large-scale and significant series of events, but u/PangeranDipanagara offered a detailed response to a very similar question here a couple of years ago, and it would be well worth reviewing that response while you wait for fresh answers to your query: