In this day and age we all live a lot closer to each other than people used to especially in the United States.  So if you are going to own a gun or more than one even, its smart to keep them locked up.  You are less likely to have a child hurt themselves, your less likely to have your guns stolen and used in the commission of a crime, and your less likely to get shot yourself if your guns are in gun safes.

Gun locks will help protect kids in your own home, but they won't necessarily stop your weapon from being stolen and used later.