Judges 17:1-6 stress the sin of self-styled worship. Judges 17:7-13 emphasize the folly of self-determined service. [source][source][source]
The writer did not call the young Levite who came to live with Micah a priest. He was evidently not a descendant of Aaron, though he was from the tribe of Levi. The Levites were, of course, living throughout Israel having received no tribal allotment of land but only cities within the territories of the other tribes. This young man had been living in Bethlehem of Judah, which was not a Levitical city ( Judges 17:7). His disregard for God"s will is obvious in his choice to live somewhere other than where God told the Levites to live (cf. Judges 17:6). [source][source][source]
"Unlike Abraham, who also set out for an unknown destination but who went with a keen sense of the calling of God, this person is shiftless. He has no passion for God, no sense of divine calling, no burden of responsibility. He is a "laid back" professional minister following the path of least resistance and waiting for an opportunity to open up." [1][source]
This young Levite decided to move elsewhere and during his travels met Micah who, desiring to "upgrade" his priesthood, invited him to live with him and become a priest to his family. Micah had been content to have his son function as his family priest, but a genuine Levite would be even better, Micah thought. Family priests had passed out of existence in Israel since God had set the tribe of Levi aside for priestly service ( Exodus 32:28-29; cf. Numbers 3:12-13). Since Micah promised to support him financially, the Levite agreed to the arrangement that Micah proposed, which involved being a spiritual adviser to his patron. Micah proceeded to set the young man apart to his service ( Judges 17:12) and superstitiously concluded that Yahweh would bless him since he had a Levite as his priest ( Judges 17:13). He was wrong, as the following chapter shows. [source][source][source]
"The apostasy of the Judges period, according to this chapter, was characterized by three observable trends1. Religious syncretism ( Judges 17:1-5).... 2. Moral relativism ( Judges 17:6).... 3. Extreme materialism ( Judges 17:7-13)." [2][source]