John 5:25 Very truly I tell you, the hour is coming and is now here when the dead will hear the voice of the Son of God—and those who hear will live.

There are lots of ways to be dead. And the process of dying can stretch out for a whole lifetime. I think that Jesus, here, was talking about dead people in the grave. They were certainly in for a big surprise. But he was also talking about the spiritually dead, the emotionally dead, the walking dead from among his own people. He still speaks to the dead, and the result is that THEY LIVE.