Most assuredly, I say to you, he who does not enter the sheepfold by the door, but climbs up some other way, the same is a thief and a robber. But he who enters by the door is the shepherd of the sheep.
To him the doorkeeper opens, and the sheep hear his voice; and he calls his own sheep by name and leads them out.
And when he brings out his own sheep, he goes before them; and the sheep follow him, for they know his voice.
Yet they will by no means follow a stranger, but will flee from him, for they do not know the voice of strangers.
— John 10:1-5