Note 13 at Joh 5:28: Jesus had just spoken of the miracle of someone being resurrected from spiritual death to new life in Jesus (Joh 5:24-25). Here He was saying if we're amazed at that, we will certainly be amazed when we see all the physically dead bodies resurrected at the end of the world.

Note 14 at Joh 5:28: No one is actually in the grave. The Bible does not teach a "soul sleep," as some people try to make it say. At physical death, the soul and the spirit separate from the body (Jas 2:26 with Re 6:9) and either go immediately to be with the Lord (Lu 23:43; 2Co 4:16-18, 5:1-10; and Php 1:23) or to hell (also Hades or Gehenna, see note 13 at Mt 5:22; Lu 16:22-23). The physical body remains in the grave and returns to dust (Ge 3:19).

The word "graves" distinguishes that Jesus was speaking about our physical bodies. Our physical bodies will be resurrected and reunited with our spirits and souls to spend eternity in either the New Jerusalem with Christ (Re 21:10-27) or the lake of fire with the devil and his angels (Re 20:14-15 and 21:8).