For it was the Lord’s doing to harden their hearts that they should come against Israel in battle, in order that they should be devoted to destruction and should receive no mercy but be destroyed, just as the Lord commanded Moses. (Joshua 11:20).
The Bible Reading Plan passage for today is Joshua 11-15. I read and re-read this verse from chapter 11. It’s a hard passage. It’s Old Testament passages like these where God gets his stern and tyrant reputation.
The John MacArthur Study Bible helps here:
God turned the Canannites’ hearts to fight in order that Israel might be his judging instrument to destroy them. They were willfully guilty of rejecting the true God with consequent great wickedness, and were as fit to remain in the land as vomit spewed out of the mouth (Leviticus 18:24-25).
Individual and national sin is a serious offense against God. RC Sproul called it cosmic treason. And for all that, God is patient. He waited 400 years for the Amorites’ sin to come to full measure. (Genesis 15:16). He gave the false prophetess Jezebel who was teaching his children sexual immorality and eating food sacrificed to idols time to repent. (Revelation 2:21). Whether it is an individual person or a national sin, He is patient. It is said in 2 Peter 3:9 that God is not willing that anyone should perish, but that all should come to repentance. This is the same God. He is immutable, unchangeable, the same yesterday, today, and forever.
His patience and willingness to give time to repent does not mean that he will forget His promise to deal with sin. Sin is a crime and all crimes have punishments. For the Canaanites, that day eventually came, and they were judged for their cosmic treason.
Our God is in the heavens; he does all that he pleases. (Psalm 115:3).