John 10:2

Verily, verily, I say unto you, He that entereth not by the door into the sheepfold, but climbeth up some other way, the same is a thief and a robber.

To him the porter openeth; and the sheep hear his voice: and he calleth his own sheep by name, and leadeth them out.

And when he putteth forth his own sheep, he goeth before them, and the sheep follow him: for they know his voice.

And a stranger will they not follow, but will flee from him: for they know not the voice of strangers.