Christ has the authority to make the dead alive equal with the Father. The Father did this so all would honor the Son even as they honor the Father. Just as the Father makes the Dead alive, brings down into hell and raises up, so does the Son, regardless where the Dead are …. above ground or in the grave, those who hear (=obey) will live:
21 “For as the Father raises the dead and gives life to them, even so the Son gives life to whom He will.
22 “For the Father judges no one, but has committed all judgment to the Son,
23 “that all should honor the Son just as they honor the Father. He who does not honor the Son does not honor the Father who sent Him.
24 “Most assuredly, I say to you, he who hears My word and believes in Him who sent Me has everlasting life, and shall not come into judgment, but has passed from death into life.
25 “Most assuredly, 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 to have life in Himself,
27 “and has given Him authority to execute judgment also, because He is the Son of Man.
28 “Do not marvel at this; for the hour is coming in which all who are in the graves will hear His voice
29 “and come forth– those who have done good, to the resurrection of life, and those who have done evil, to the resurrection of condemnation. (Jn. 5:21-29 NKJ)
JESUS IS EQUAL TO GOD IN HIS POWER AND SOVEREIGNTY
“For just as the Father raises the dead and gives them life, even so the Son also gives life to whom He wishes.” (5:21)
By asserting His equality with God, Jesus claimed that He had the parallel power with God to raise the dead just as the Father raises the dead and gives them life. The Bible teaches that only God has the power to give life to the dead (Deut. 32:39; 1 Sam. 2:6; 2 Kings 5:7; Acts 26:8; 2 Cor. 1:9; Heb. 11:19), and the Old Testament records several instances where He did so (1 Kings 17:17–24; 2 Kings 4:32–37; 13:20–21). Because His power is the same as the Father, Jesus Christ is able to raise the physically dead (11:25–44; Matt. 9:18–25; Luke 7:11–15; cf. John 6:39–40, 44). Moreover, He has the power to give spiritual life to the spiritually dead. “Whoever drinks of the water that I will give him,” Jesus promised, “shall never thirst; but the water that I will give him will become in him a well of water springing up to eternal life” (4:14). In John 6 He admonished His hearers, “Do not work for the food which perishes, but for the food which endures to eternal life, which the Son of Man will give to you,” because He is “the bread of God … which comes down out of heaven, and gives life to the world” (vv. 27, 33; cf. vv. 35, 48, 54; 1:4; 10:28; 11:25; 14:6; 17:2).
Unlike Elijah (1 Kings 17:22) and Elisha (2 Kings 4:34–35), Jesus did not merely act as God’s representative when He raised the dead, but as God Himself. The Son Himself gives resurrection and spiritual life to whom He wishes. As God is the source of life, so Jesus Christ is the source of life.-MacArthur, J. F., Jr. (2006). John 1–11 (pp. 188–189). Moody Press.
28 “Do not marvel at this; for the hour is coming in which all who are in the graves will hear His voice
29 “and come forth– those who have done good, to the resurrection of life, and those who have done evil, to the resurrection of condemnation. (Jn. 5:21-29 NKJ)
The Key question to answer, “when does the hour arrive?”. At judgment Day, 1000 years after the Millennial reign of Christ (Rev. 20:11-15). Or does scripture say the dead heard His voice before that time?
18 For Christ also suffered once for sins, the just for the unjust, that He might bring us to God, being put to death in the flesh but made alive by the Spirit,
19 by whom also He went and preached to the spirits in prison, (1 Pet. 3:18-19 NKJ)6 For this reason the gospel was preached also to those who are dead, that they might be judged according to men in the flesh, but live according to God in the spirit. (1 Pet. 4:6 NKJ)
27 And as it is appointed for men to die once, but after this the judgment,
28 so Christ was offered once to bear the sins of many. To those who eagerly wait for Him He will appear a second time, apart from sin, for salvation. (Heb. 9:27-28 NKJ)8 Therefore He says: “When He ascended on high, He led captivity captive, And gave gifts to men.”
9 (Now this, “He ascended “– what does it mean but that He also first descended into the lower parts of the earth?
10 He who descended is also the One who ascended far above all the heavens, that He might fill all things.) (Eph. 4:8-10 NKJ)14 “I will ransom them from the power of the grave; I will redeem them from death. O Death, I will be your plagues! O Grave, I will be your destruction! Pity is hidden from My eyes.” (Hos. 13:14 NKJ)
Another question to answer, “to hear” in this context signifies “obediently hearing, believing” (John 5:24-25) and this separates those who rise to life from those who rise to condemnation.
Its how these “in the grave” react to Christ’s voice they heard while in the grave that determines their fate:
28 Marvel not at this: for the hour is coming, in the which all that are in the graves shall hear his voice (ἀκούσονται τῆς φωνῆς),
29 And shall come forth; they that have done (ποιήσαντες aorist participle) good, unto the resurrection of life; and they that have done (πράξαντες aorist participle) evil, unto the resurrection of damnation. (Jn. 5:21-29 KJV)
Many commentators minimize the subsequent (following) use of the aorist participle. Even such scholars as Robertson and Moulton, who recognize that the participle is not time-bound, resist this category of usage. But there are a number of examples in biblical and extra-biblical Greek where an aorist participle is used to refer to an action occurring after the action of the main verb. In virtually all of these examples, the aorist participle is placed after the main verb in syntactical order.-Porter, S. E. (1999). Idioms of the Greek New Testament (p. 189). JSOT.