What does Judges 17:13 mean?

The verse shows how far knowledge of the Lord and His will had fallen among the people of Israel (Judges 17:6). One reason God commanded Israel to wipe out the idol-worshipping nations of Canaan was to prevent Israel from imitating their moral crimes, such as child sacrifice and sexual depravity (Deuteronomy 12:29–32). Another was to stop Israel from becoming spiritually confused, as Micah seems to be. Results such as what's described in this passage (Judges 17:1–5, 7–12) are exactly why God was so angry when Israel failed to maintain those standards.

At this phase of the era of the judges (Judges 2:16–19), the people have thoroughly mixed their worship of the One True God with the religious practices of the people of Canaan. This makes them, it seems, clueless of the great sins they are committing by violating so many of God's commands (Exodus 20:1–17). One generation has not properly taught the next to follow the ways of the Lord. That generation did even less. Over time, the people have been left to make up their spiritual practices according to whatever suits their desires (Judges 17:6).

Micah is thrilled to have found a genuine man of the tribe of Levi. He seems to think using a priest from that line is like owning another magical totem. He is convinced the Lord will be pleased with this and will make him wealthy, healthy, and wise. That's what gods are for in Micah's culture: Make them happy, and they will give you a good life. This, unfortunately, is still part of false religion today. Many people delude themselves into thinking that worship is a means to prosperity, and plenty of frauds are ready to prey on that weakness (1 Timothy 6:5–6).

It's not explicitly stated as to whether Micah's Levite priest knew better. Had he been trained in the Law of Moses, who is said to be his grandfather (Judges 18:30)? Did he know this house religion of Micah's was violating God's commands about worshiping other gods, making carved images to be objects of worship, and worshiping the Lord outside of a central location approved by God (Numbers 3:5–10)? Whatever he might know, this newly hired priest seems happy to leave those concerns unspoken. Most likely, he fears causing offense to his new employer over inconvenient truths related to the Lord.