In christianity fighting for God is wrong but fighting for $$atan is good?if no then what is cru$ade?

When u raise a generation preaching them that fighting for God is taboo then suddenly u decide a cru$ade but u cant convince your soldiers to go fight anymore unless u tempt them by a high paid cos they were taught that fighting for God is wrong but now money will convince them to go fight without caring what the goal of the war as long as they get $$$$ which makes them actually fighting for $$$atan instead of God,on the other hand the muslim guys dedicate their money and bravery and life for God,why christianity messes the balance of the mankind and makes him employes his fight instinct for $$atan instead of God while mankind as a creature is not supposed to fight for material goals?