And when I saw that you would not save me, I took my life in my hand and crossed over against the Ammonites, and the LORD gave them into my hand. Why then have you come up to me this day to fight against me?
Jephthah's rule as a judge in Israel degenerated into civil war and internal strife. It is sad to see. The Ephraimite tribe is upset that they played no role in Jephthah's major battle. They attack his primarily Gileadite army and over the course of the battle, Jephthah's men capture and kill (seemingly one by one - see Judges 12:5-6) 42,000 men of the tribe of Ephraim.
This was a tragedy because Israel could not really afford to lose that many fighting men. It was an atrocity because it became a kind of ethnic cleansing among God's people. Ephraimites were sorted out by their dialect and killed on the spot. It was actually kind of gruesome.
But when people do not seek the Lord and forge out on their own skills and power alone, this sort of thing is inevitable. From a pure military standpoint, I am sure that Jephthah thought this strategy was the best for preserving the nation and his rule. But from a personal and spiritual standpoint, Israel was still being destroyed. This time it came from within.
My observation is that the worst things can happen to the testimony of God's people from within their midst. We don't need to have enemies from the outside attacking us to fail. We can be victimized by infighting just as easily. We should always guard our peace by staying close to Christ and to our brothers and sisters in Christ. The beauty and the power are too precious to lose through infighting.
- Prepare your minds for action.
1 Peter 1:13