[The shepherd] calls his own sheep by name and leads them out. When he has brought all his own outside, he goes ahead of them. The sheep follow him because they know his voice…
I have other sheep that are not from this sheep pen; I must bring them also, and they will listen to my voice. (John 10:3-4, 16)
In a lot of ways, John 10 echoes chapter 8. In chapter 8, Jesus says those who are truly from God listen to and obey him.
You see the same theme here. The main characteristic of Jesus’ sheep is that they listen to and obey him.
A sheep is sometimes dumb and will wander away from its shepherd. But ultimately it still recognizes and delights in its shepherd’s voice. And when the shepherd calls, it comes running.
The blind man that was healed in chapter 9 was one of Jesus’ sheep. When Jesus called, he delighted in his Shepherd and followed. (John 9:35-38)
The disabled man in chapter 5, on the other hand, I have doubts about. Though Jesus healed him, we see no signs that he delighted in and followed his Shepherd. Rather, to save his own neck, he reported Jesus to the religious leaders. (John 5:14-16)
That said, none of us are perfect sheep.
All of us sometimes fail and stray from our Shepherd.
How then do we know if we are truly his sheep?
It shows in our foundational attitude toward our Shepherd: We trust him, delighting in his voice, and following wherever he leads.
Is that your heart?
Whose sheep are you?
Moment to Moment (Bible blog) 