They are breaking into your home to steal your things or harm you, being armed with a firearm prevents that from happening. If they still continue to break in

They are breaking into your home to steal your things or harm you, being armed with a firearm prevents that from happening. If they still continue to break in after seeing you are armed with a firearm, you can just simply just shoot them once they get inside as your life was in danger and you also solve that from ever happening again from that person.