What does Judges 6:1 mean?

The repetitive, downward spiral of the era of the judges (Judges 2:11–19) begins again. After Deborah and Barak defeat the Canaanites (Judges 4:23–24) Israel is free and living at peace in the land. During that brief period, the people seem to be following the ways of the Lord. Then a new generation comes along, who promptly returns to worshipping Baal and the other false gods of Canaan. Service of any false god is evil in and of itself since it is a betrayal of the one true God. That's even more the case for Israel, who has a special relationship with the Creator. Worship of the Canaanite deities also involves vile practices including sexual depravity and human sacrifice.

The Lord is faithful to respond to Israel's evil by allowing them to be oppressed yet again. This time, Israel's oppressor will be the Midianites. Midian was one of the sons of Abraham and a wife called Keturah, whom he married after the death of Sarah (Genesis 25:1–2). The descendants of Midian grew to be a persistent people, often existing as nomads in the ancient near east. Israel had both positive and negative interactions with Midian over the course of their shared history. Later in Israel's wilderness wandering, however, Midian harassed the Israelites and tried to lead them away from God (Numbers 25:16–18). This eventually led to war against Midian (Numbers 31).

Now, many years later, God has allowed the Midianites to grow strong again. They were settled during this era east of the Jordan River, but they had begun to cross over to the western side and push farther and farther into the land. The Lord gives Israel into their hands for seven years because of Israel's evil practices.