What does it mean to dream of killing spiders?

It could mean several things:

You are chasing after evil because you have the Word of God, ready to kill it, but evil is scared of you. It's running away because your light shines bright that it can't stand to be near you.

Maybe if you are afraid of Spiders, it means that you overcame your fear, and now your not afraid to take charge. The spiders are now afraid of you.

Spiders or wicked are spread all over the world and it is our job to defeat it. So whevever anybody tries to kill something/someone they are going to try to escape. So it could mean that you are going to kill the wicked in the world.

Hope this helps! :) Have a nice day