This is a common problem among most (if not all) of the people groups in this part of the world. And evidently, it has been a problem among Christians in many contexts for many centuries, because Paul talked about it too:
For you yourselves know how you ought to imitate us, because we were not idle when we were with you, nor did we eat anyone's bread without paying for it, but with toil and labor we worked night and day, that we might not be a burden to any of you. It was not because we do not have that right, but to give you in ourselves an example to imitate. For even when we were with you, we would give you this command: If anyone is not willing to work, let him not eat. (2Thes 3:7-9)
The Dong Christians simply do not have examples to imitate. They do not know any regular Christians who have a regular job, yet live out their lives fully for Christ in their daily lives. Let us pray both for them to grow in their understanding of scripture and for the Lord to provide some working Christian examples which they could imitate.