God’s policeman – Chukkat
The sidra talks of Sefer Milchamot HaShem, “The Book of the Wars of the Lord” (Num. 21:14).
This does not necessarily justify history’s religious wars in which a religion was adamant that it was fighting for the sake of God.
The real meaning of the phrase is that there are some human events and philosophies which are so opposed to what God stands for that He has an on-going battle with them.
An example is the cruel, callous, cowardly Amalek, about whom the Torah says that God is at war with him forever.
What God insists upon is “Love your neighbour” (don’t undermine or demonise him), “Relieve your neighbour’s laden animal” (don’t make it suffer because of its owner), “Do not bear false witness” (don’t twist words or the truth).
Fighting for God is fighting against His enemies.