1. Israel had no king (1-12, 27-29)
Dan was the last tribe to receive their inheritance. Without a king, no one served their problem. The unity the tribes of Israel once shared when they first entered the promised land had dissipated. There was no common vision or mission. Genesis 49:17 says that Dan was like a snake in the grass. With this spirit, they went to the hill country of Ephraim and spied out Laish, an unprotected, peaceful and prosperous Canaanite city. They attacked Laish with 600 armed men, easily conquered it, and renamed it Dan. Without a king, everyone was out for themselves and lived for their own kingdom.
2. The Danites set up their own religion (13-26, 30-31)
When the Danites returned to conquer Laish, they stole Micah's priest, household gods and idol. They followed this false religion until they were taken into captivity (30). The bad influence of Micah's idolatry led astray an entire tribe. When people don't have God as their king, they easily end up in idol worship and spiritual captivity.