In context, it says that his (Jesus Christ's) sheep listen to him, he knows them, and they follow (obey) him. He gives them eternal life, and they will never perish:
27My sheep hear my voice, and I know them, and they follow me. 28 I give them eternal life, and they will never perish, and no one will snatch them out of my hand. 29 My Father, who has given them to me, is greater than all, and no one is able to snatch them out of the Father's hand.
The "good news" is that all created men will hear His voice after the death of their flesh;
John 5:
25: "Truly, truly,
I say to you, the hour is coming, and now is, when the dead will hear the voice of the Son of God, and those who hear will live.
26: For as the Father has life in himself, so he has granted the Son also to have life in himself,
27: and has given him authority to execute judgment, because he is the Son of man.
28:
Do not marvel at this; for the hour is coming when all who are in the tombs will hear his voice.
Ezekiel 37:
1: The hand of the LORD was upon me, and he brought me out by the Spirit of the LORD, and set me down in the midst of the valley;
it was full of bones.
2: And
he led me round among them; and behold, there were very many upon the valley; and lo, they were very dry.
3: And
he said to me, "Son of man, can these bones live?" And I answered, "O Lord GOD, thou knowest."
4: Again he said to me, "Prophesy to these bones, and say to them, O dry bones, hear the word of the LORD.
5: Thus
says the Lord GOD to these bones: Behold, I will cause breath to enter you, and you shall live.
6: And
I will lay sinews upon you, and will cause flesh to come upon you, and cover you with skin, and put breath in you, and you shall live; and you shall know that I am the LORD."
7: So I prophesied as I was commanded; and as I prophesied, there was a noise, and behold, a rattling; and the bones came together, bone to its bone.
8: And as I looked, there were sinews on them, and flesh had come upon them, and skin had covered them; but there was no breath in them.
9: Then he said to me, "Prophesy to the breath, prophesy, son of man, and say to the breath, Thus says the Lord GOD: Come from the four winds, O breath, and breathe upon these slain, that they may live."
10:
So I prophesied as he commanded me, and the breath came into them, and they lived, and stood upon their feet, an exceedingly great host.
11: Then he said to me, "Son of man, these bones are the whole house of Israel. Behold, they say, `Our bones are dried up, and our hope is lost; we are clean cut off.'
12: Therefore prophesy, and say to them, Thus says the Lord GOD: Behold, I will open your graves, and raise you from your graves, O my people; and I will bring you home into the land of Israel.
13: And
you shall know that I am the LORD, when I open your graves, and raise you from your graves, O my people.
14: And
I will put my Spirit within you, and you shall live, and I will place you in your own land; then you shall know that I, the LORD, have spoken, and I have done it, says the LORD." 
