The Midianites oppressed Israel in an interesting way. They would let Israel do all the work of planting, tending, and harvesting crops and then invade to take away their food. Gideon is told by God that he is to deliver Israel. Gideon attacks the false gods that Israel is worshiping and then asks God to prove to him that he is supposed to attack the Midianites.
There is an interesting contrast in this chapter. Gideon attacks Baal and the challenge is made for Baal to defend himself, which Baal obviously can’t do. Gideon asks God for a sign, and God delivers. We worship a powerful God! We should be doing what he tells us to do instead of putting our energy into things that are powerless to make a real difference in our lives.