This is a different kind of God. He has been proving who Yahweh is throughout the plagues and Exodus. He has firmly established how different Yahweh is from all the other gods.
A different kind of God develops a different kind of relationship with his people. In preparation for the giving of the commandments on Mt. Sinai, God says, "you will be to me a kingdom of priests, my holy nation" (19:6).
Most nations of that era had their gods and only a few out of the society served as priests to communicate with the gods. Yahweh's kingdom is different: the whole kingdom is made up of priests. In other words, he wants direct contact with everybody, instead of a few people who are set apart (holy) as priests.
Israel went astray from that concept, but the new kingdom is exactly that. That is the relationship he wants with the Dong people.
He does not want them to fear the unknown spiritual powers and seek the help of a witch doctor. He wants them to know him and commune personally with him. He has given the life of his only son in order to establish a perfect kingdom that does function as he desires.
Just as the climax of the Exodus was the giving of the covenant at Mt. Sinai, so joining God's kingdom of priests will be the climax of his work among the Dong people. Let us pray it will come about.
King of All, we see and understand your desire for your kingdom. We see that you intend for every soul in your kingdom to gain access to the King himself. We see also that you want to bring the Dong people into the kingdom. You alone know the path to bring that about, and we pray that you will accomplish these acts to your glory. May all our prayers and actions help work to this saving climax.