28 Do not marvel at this; for the hour is coming in which all who are in the graves will hear His voice
Verses 28 and 29 indicate that Jesus’ judgment must await resurrection.
Verses 28-30 discuss the future of those who believe on Christ. There are four truths taught here:
Physical death is not the end of existence.
There are two forms of existence beyond the grave: eternal loss and eternal salvation.
The way to enter the existence of eternal salvation is by relationship to Jesus.
There are two resurrections:
Resurrection to life (the first resurrection), and
Resurrection to damnation.
28 Do not marvel at this;
“At this” refers to the previous verses where Jesus referred to His calling people from their graves on the last day.
The Jews were already in the process of marveling at Jesus’ words. Unbelieving Jews in Jesus’ audience were astonished at His claim to have the ability to make the determination as to who has eternal life. It was shocking to them. He was about to offer another astounding claim in this verse.
for the hour is coming in which all who are in the graves will hear His voice
All the bodily dead will hear the voice of Jesus. Jesus will raise both the just dead and the unjust dead. The just dead will move into eternal life with God and the unjust will go into eternal condemnation.
Not only could Jesus offer a spiritual resurrection, but He offered a bodily resurrection. There is a day coming when those in the tomb or grave will hear His voice. This is the final apocalyptic resurrection. The Messiah will shout at the Rapture (1 Th 4:16).
There are different judgments for different people.
There is no such thing as a general judgment. Judgments are separated by the Millennium. The dead in Christ will rise first at the Rapture (1 Th 4:16). Old Testament saints and Tribulation martyrs will rise later. The resurrection of the damned will occur a thousand years later (Re 20:5)—the resurrection of judgment called the Great White Throne judgment for non-believers of all ages.
There are two resurrections in verses 28-29 (Re 20:4-6 and 20:11-15). The first resurrection is of those who are saved; it occurs at the Rapture of the church. During the Tribulation and after the Rapture many will turn to the Messiah. These believers will be raised at the end of the Tribulation with Old Testament saints. Those events are what we call the “first resurrection.”