Jesus first tells the man to follow the commandments, to which he replies that he has followed them from birth. The rich man thinks of the commandments as a set of rules, but the Ten Commandments (and all the Law) are really about relationship. Just take a look; every one of the Ten Commandments speaks to relationship, whether with God, our parents, our wife, or neighbors.
So, Jesus gives him something to do that does not fit in his view at all. The rich man wanted affirmation that he had already made it or at most to be given one last chore to tick off his list. Instead, he was told to give up everything.
The Dong people are animists. They think exactly like this rich man. If something goes wrong, they ask shamans what they must do. They daily offer sacrifices, incense, and food to their ancestors and to the spirits.
They cannot earn eternal life, though. As they see the Jesus Film, pray that the one-ness of Jesus and the Father will be clear to them. Pray that they will see that Christ is calling them to that same one-ness. That is how they will inherit eternal life.