It happened, as soon as Gideon was dead, that the children of Israel turned again, and played the prostitute after the Baals, and made Baal Berith their god.
Most of the major judges in the Book of Judges lacked character that we would call "above reproach" (1 Timothy 3:2). God uses vessels unto dishonor as well as vessels unto honor to accomplish His work (2 Timothy 2:20-21). This in no way justifies ungodliness. It simply magnifies the sovereignty and grace of God in using rough material if He chooses to do so for His own purposes.