Micah wants to ensure he is following good liturgical protocol, at least on the outside. That he wants the Levite to function as his priest
reveals that he is insecure about his man-made religion. He is plagued by doubts, even though he has built his own shrine, arranged for the right liturgical things, and ordained his own son as his priest. He has no solid foundation for his faith.1
10 And Micah said to him, “Stay with me, and be to me a father and a priest, and I will give you ten pieces of silver a year and a suit of clothes and your living.” And the Levite went in.