How do God's good angels fight Lucifer's bad angels if they cannot kill each other?

Answer 1

It is all about territory. If a person declares for the Living God, such a person becomes a marked territory of God and attracts a hedge or covering of God as evidenced in the story if Job. If one does not declare for God by default such a person belongs to Satan aka lucifer.

The Lord gave Adam dominion which he handed back to the devil by carelessness or by simply not guarding that which was entrusted to him; since this dominion is for an appointed time, Satan and his bad angels cannot be killed or tormented yet as was substatiated by the legions that spoke to Jesus from the possessed that ended up in the swine that entered the water.

However, though they cannot kill each other, every side abides by a strict principle. As far as the hedge is above every child of God, all the bad angels or demons can do is to entice us to come out of the hedge so that God who does not defile Himself will stand aside and watch the assault of the demons while the Holy Spirit in us goes into a serious damage control to bring us back under the safety of the hedge.

Psalm 91 illustrates this security we have under the hedge. The enemy can try but we will take authority over their activities standing on the word of God and the Blood of Jesus.

They cannot kill each other but both sides plays by a strict biblical principle. As believers we must hold on to our faith, and refuse fear which is the opposite of faith because fear brings doubt and doubts according James 1:6-8 exposes us to the lucifer and his gang. My favorite place to strengthen my faith during trials is 2nd Corinthian 4:7-9; we are hard pressed on all sides but not crushed...