Judges 6:32
Therefore on that day he called him Jerubbaal, saying, Let Baal plead against him, because he hath thrown down his altar. Therefore on that day he called him Jerubbaal, saying, Let Baal plead against him, because he hath thrown down his altar.
Judges 6 stands in the repeated cycle of Israel's backsliding and chastisement followed by confession and deliverance. In that pattern God raised up faithful and valiant men to put down idolatry and to deliver Israel from their enemies. When the deliverer died the people gradually returned to their idols.
On the day Gideon threw down Baal's altar he was called Jerubbaal. The name means let Baal plead or contend for himself against him. The challenge exposes that a god unable to defend his own altar cannot be trusted to protect his worshipers.