The second-best security is a good lock. The first-best security is having nothing to steal.
The trouble with the first-best security is that you end up living such a boring boring life. No one ever steals your stuff, but you never HAVE any stuff to steal! If you wanna be a monk, that's of course your decision and we support and love you. But if you'd rather enjoy what the world has to offer and keep a few things, hey, get a lock.