You’re at home and you hear a knock on your door. It’s ingrained in most people that this sound is some kind of command to them to proceed to the door and open it. Why would you do this? Do you usually do things because someone you don’t know wants you to do them? At this point, you don’t know who is on the other side of that door. It’s your door. You don’t need to do anything that you don’t want to do. And, you do not want to just open the door.
 

If you decide that you want to find out what’s outside, then you should have already considered where in your home you can see outside your door. A peephole isn’t it. Find a window, mount a small mirror outside, get a closed-circuit camera and a monitor. See what’s outside and what’s behind it. Some people will yell through the door asking who’s there. Who cares? If you don’t know, why trust what the entity outside says in the first place?

One way to avoid the problem entirely is to be absolutely sure that the people who would be likely to come to your home know to call you in advance. So, no call and a knock means it’s not somebody you know.

Even when you think you know who it is, stay clear of the door in case it comes crashing in. If you’re armed (hopefully you are always armed), give some thought to more powerful weapons when dealing with doors and home entry. While I always have a 9mm pistol, in the extremely rare occasions that someone unannounced has arrived, I prefer a 12 gauge shotgun as I then have the option of shooting through the door if necessary, and if the door is breached, I have theoretically better knockdown power in a close-range situation where it’s likely there will be several attackers.

Work out the details of all this now, before you need to do them. Your door isn’t an invitation to others, it’s a way to keep them out. Don’t just open it and yourself to an unknown situation which is easily avoidable by simply not answering their knock. And, if it escalates, you will be ready to take care of the problem.