Understanding spiritual warfare starts with appreciating that "the battle is the Lord's". It is His fight against His enemies in which we are involved as "helpers of the war" like those who gathered at Ziklag to help David in his. (1 Chronicles 12:1) He who is not with Him is against Him and he who does not gather with Him scatters. (Matthew 12:30) That way, one who fights when God fights, will not fight when God is not fighting and fights about what God is fighting about.