I am reading Christianity Rediscovered by Vincent Donovan.  He was a Catholic missionary to the Masai more than 25 years ago.  He decided that the program-based missions that were currently operating were largely ineffective and decided to just go to the villages, and with their permission, tell them the Gospel.  He spent a year going into 6 villages, spending 1 day a week in each one.  After a year, he simply asked if they wanted to become followers of Christ.  Most did, but there were a few who didn't, so he left them never to return.

The villages who chose to become Christian, he baptized and then assisted them in setting up their own cultural liturgies and traditions.  The only two that he gave them was baptism and the Eucharist.  He agonized of what was Western Christianity and what was actually Christ.