I think if everyone want to learn on why we need gun or where do guns needed for it will be good. But it is impossible for us to know about it because everyone who have gun has a power. A power to kill a person no matter who is it. A gun can be a self defense tool but it can show us that a gun can cause some evil scenarios.
Ok fine, but doesn't any person, armed or not, have the power to kill another person? It's literally hard to find something in the house that could not be used to kill someone. You can kill a person with a corkscrew, a chainsaw, a nail gun, a glass, a screwdriver, a fork, a frying pan, a string, a baseball bat, and so on. Most of these things are close combat but it's easy to get close to someone when they're standing in a line at a store, or watching a movie in a cinema. It's the intent to kill that counts. If I wanted to I could murder my whole family while they sleep with a kitchen knife, but I don't because I'm not mentally ill. You won't change the fact that some people have murderous intent by denying everyone the right to own a firearm and statistics prove it.