And all these, having gained approval through their faith, did not receive what was promised, because God had provided something better for us, so that apart from us they would not be made perfect...
But you have come to Mount Zion and to the city of the living God, the heavenly Jerusalem, and to myriads of angels, to the general assembly and church of the firstborn who are enrolled in heaven, and to God, the Judge of all, and to the spirits of the righteous made perfect, and to Jesus, the mediator of a new covenant, and to the sprinkled blood, which speaks better than the blood of Abel.
Heb 11:39-40, 12:22-24 NASU
Christians choose, in response to God's invitation, to die now to the flesh, so that they will not die in a more vital way. This is not just a metaphor, but a real choice to die in a fundamental way, to be separated from things of this world that are passing away, in order to live in relation to God. We die with Christ (Rom. 6:9-10) so that death has no more mastery of us, that we may live to God. This chosen death transforms us from death to life, that the life we receive may not be subject to sin and hence to death, but may continue forever with God, with no indication of any interruption in the realm of death (2 Cor. 5:14-17).
The perspective of ongoing life caused the saints of the New Testament to have a more joyous view of death than did the saints of the Old Testament. Unlike Hezekiah or David, Paul expressed a joyful anticipation of being closer to the Lord when he died, even before the return of Christ. Paul expected that he would gain in the death of his body; that in leaving the flesh he would "depart and be with Christ, which is far better."(Phili. 1:21-23). Again, Paul said that he would be "well pleased ... to be absent from the body and to be present with the Lord."(II Cor. 5:8). This improvement in expectation was possible because Jesus had opened a new and living way of access to the Father through His own flesh (Heb. 10:19-22). We have an access to heaven (where Jesus is) that was not previously available, though it was eagerly anticipated by those who died in the faith of the Old Testament (Heb. 11:39-40).
Considering the expectation of those Old Testament saints, it seems that Hades, the realm of the dead, had two divisions, that Satan's power of death at least was limited and God's people were kept apart from those who were none of His. Those who were of their father the devil were in a place described as torment (Luke 16:23), and those who the Lord would claim were in a place described as Abraham's bosom or paradise (Luke 16:22, Luke 23:43 w/Acts 2:27). As we have seen, when Jesus died His soul departed for paradise in Hades, but Hades could not hold him. Jesus broke the bonds of death and brought a new dispensation into being, a new order in which His promises could be fulfilled, that His true disciples would never see or taste death (John 8:51-52), that they have passed from death to life (John 5:24-25, I John 3:14). They will never die (John 6:50, 11:26) because death has no more dominion over them (Rom. 6:7-9). Death doesn't matter anymore in the face of Christ's victory, which we share in, because now nothing can come between us and Him (including death, Rom. 8:37-39, I Cor. 3:21-23). When Christians "die" it is only the flesh falling asleep (I Thes. 4:15), not the separation of a saved soul from its loving master, who has tasted death for them already (Heb. 2:9). Anyone who tastes death now, who experiences the captivity of Hades and its separation from the goal, does so because they have chosen not to accept Christ's work and the freedom from death He offers. Those who "die" in the Lord do not have the "taste of death" or "see death", but rather since Jesus has defeated Satan and has the keys of death and Hades, they live and reign with Christ (as souls in heaven, not glorified spiritual beings yet, Rev. 20:4-6). Meanwhile, even as they live and reign with Christ (as also in II Tim. 2:11-12, and note when Christ reigns I Cor. 15:24-28), they anticipate with joyful expectation the restoration of all things when they will return with Jesus for the resurrection (Acts 3:19-21, I Thes. 4:14, Jude 14-15) and receive the glorious resurrection body described by Paul in I Cor. 15.
Already, "when He ascended up on high He led captivity captive" (Eph. 4:8), He took charge of death which held us in bondage, and when He returns to glorify His saints and overthrow evildoers in judgement, He will cast death itself into the lake of fire, along with Hades the abode of the dead (Rev. 20:14). There are those who will be in death and Hades until that great day of judgement (Rev. 20:13), those who do not have part in the "first resurrection" (Rev. 20:4-6, Rom. 6, I Cor. 15:20). As man chose to make death in the first place, by sin, he can choose to keep it now, to still be subject to captivity by rejecting Christ. As is announced in Rev. 14:13, for John to write, "Blessed are the dead who die in the Lord from now on. Yes, says the Spirit, that they may rest from their labors, and their works follow them." Where can we find such rest? Jesus says we find it when we come to Him (Matt. 11:28-30). Rest from your labors is found with Jesus (Heb. 4:1-11), and the New Testament expectation is that when their bodies die, that is where His people will be, not in Hades, but in heaven with Him. The soul of the Christian, the thinking and feeling part of man, does not experience separation from its Lord, but rather is welcomed into His presence, there to reign with Him until the resurrection and glorification in judgment. Jesus told the disciples,"A little while longer and the world will see me no more, but you will see me. Because I live, you will live also."(John 14:19). They (we) go right on seeing and living, even while anticipating more to come when the body itself comes forth from the grave at His second coming (John 5:28-29).
Finally, note that while there are various references to departed saints being with the Lord or in heaven or not dying in the New Testament epistles and Revelation (Acts 7:59, II Cor. 5:8, Phil. 1:23, I Thes. 4:14, Jude 14, Rev. 4:1/6:9-11, Rev. 20:4), there is not a single reference to a New Testament saint being in Hades in any way whatsoever. Hades is mentioned only once in the epistles when Paul says,"O death, where is your sting? O Hades, where is your victory? The sting of death is sin, and the strength of sin is the law. But thanks be to God, who gives us the victory through our Lord Jesus Christ."(1 Cor. 15:55-56). Rather than Hades having the victory over us, holding us captive, we have victory in Christ and death has no more dominion over us. The sting of death, sin, has been removed by the victory of Jesus. Hades has no victory over the child of God. When the Lord returns with His holy ones, death will be "swallowed up in victory", death and Hades will be cast into the lake of fire, but already the sting of death is gone (in Christ) and the grave (Hades) has no victory over those who themselves have the victory in Christ.
Some other passages to consider on the theme of ongoing life apart from death, due to Jesus' work: Rom. 8, esp. 9-11, 13; II Tim. 1:10; Rom. 14:8-9; I Pet. 2:24-25 w/John 10:27-29; John 17:3; Eph. 2:1-7; Col. 2:11-15; Col. 3:3-4; Heb. 12:23(22-24); and, where is "the family"... Eph. 3:14-15?
Last of all, consider Rev. 7:9-17, and ponder whether this is before or after the judgment, noting that it is a scene before the throne, and so in heaven, but that there is a temple (15), whereas in the New Jerusalem after the judgment there is none (21:22), that they serve day and night (15) whereas after judgment there is no night there (21:25), that they are sheltered from sun and heat (16) but after judgment there is no sun (21:23) and that the Lamb still occupies the throne (17). Yet, these are the ones who "come out of the great tribulation" and whose tears are being wiped away by their God. Jesus has beaten death, and in him his people are victorious over it as well, already, and always.