Judges 3:2, Taught to war. Among other reasons, YHVH allowed some of the Canaanites to remain in the land of Israel not only as a spiritual test to the Israelites to see if they would remain faithful to YHVH in the face of worldly pressures (Judg 3:4), but so that they wouldn’t forget how to wage warfare.
Once a person or a people have received their inheritance, it’s easy to become soft, lazy and complacent. If they don’t fight to hang on to their inheritance, they will usually end up losing it. This often happens to those who become the beneficiaries of sudden wealth (e.g., through inheritance or the lottery). They have never learned how to appreciate and to manage properly their resources because they never had to work hard to earn it, so they don’t value it as much as someone who started with nothing from scratch.
Each new generation must learn to maintain what has been given to them and then fight to hold on to it.
Likewise, each new disciple of Yeshua must also learn the principles of spiritual warfare and how to resist the enemy, so they don’t lose the precious spiritual gifts YHVH has given them through Yeshua the Messiah. If they take their spiritual inheritance for granted and become complacent, YHVH will allow their enemies to rise up and to test them.
Some disciples who have drifted away from YHVH will pass the test and defeat the enemies and return to YHVH. Others will continue down the slippery slope of drifting away from YHVH and will slowly “intermarry” with the enemy. This is what happened to the majority of Israelites during the time of the judges as we see in verse six of this chapter.