God’s chosen people are not spared from testing, especially God’s people. In this passage, the israelites were already settled in the land. As you can read, God did not destroy all the inhabitants that israel found when they first got there. He left some to test the people.
Testing is very important in one’s faith. Without testing, faith becomes an exercise in futility. God’s original plan for israel was that He will help them destroy all the inhabitants of Canaan thereby purging the land of evil. For many reasons, Israel was not able to accomplish this task.
A major reason is the lack of faith.
Israel always felt they were not strong enough even though God already told them that He will be with them. The Promised Land was a test of faith. And Israel was consistently faithless.
During the time period of judges 3, it was clear that God was now going through a different approach with Israel. He is letting the original inhabitants live among the Israelite so that those who did not experience war will not be idle. They will always have threats among them, much like today.
Israel did not follow God’s original plan for them and they had to live with the consequence. They will always have trouble among them.
Following God is not easy, but we need to have faith. The Israelites heard God and saw His marvelous works but still they failed. John 20:29, “Then Jesus told him, ‘You believe because you have seen me. Blessed are those who believe without seeing me.'”
Following God has its rewards, disobeying can mean more testing. Let’s all try to have faith God when He tells us to follow Him.