One of the definitive doctrines of Christadelphians is that the hope of the just is eternal bodily life on earth after the resurrection, and not an immaterial existence in the heavens beginning at death (or the Rapture).
At first glance, it appears that the gulf between this belief system and the popular Christian belief in a heavenly afterlife is vast and insurmountable. Most Christadelphians would say that they do not share 'one hope' (Eph. 4:5) with other Christians. For Christadelphians who think this, there are two books I would encourage you to read. The first is Surprised by Hope: Rethinking Heaven, the Resurrection, and the Mission of the Church, by Anglican bishop emeritus and eminent New Testament scholar N.T. Wright. The second is Sense and Nonsense about Heaven and Hell, by Evangelical scholars Kenneth D. Boa and Robert M. Bowman, Jr.
Both of these books (and many others) make what amounts to a critique of the popular Christian belief that disembodied heaven-going at death (or at the rapture) is the hope revealed in the Bible. They both insist that our hope is resurrection to an eternal bodily existence, just as Christ was raised to an eternal bodily existence.
This movement is not new - Boa and Bowman draw heavily on a 1965 essay by the prominent German theologian Oscar Cullman entitled, "Immortality of the Soul or Resurrection of the Dead?" Cullman noted at the time that his ideas had provoked both great enthusiasm and great hostility. The enthusiasm appears not to have abated in the last 50 years but rather continues to grow and flourish.
This shift in direction should not be understood as a wholesale adoption of Christadelphian ideas. All of the above writers argue biblically for some kind of conscious existence after death. However, this is not the final reward; it is merely an 'intermediate state' for those awaiting the resurrection. Boa and Bowman do not mention Christadelphians but devote several pages to refuting the doctrine of annihilation at death as espoused by Jehovah's Witnesses and Seventh Day Adventists. This includes positive evidence for the 'intermediate state' as well as refuting alleged biblical support for annihilation.
The Christadelphian may respond, "But what about the consummated kingdom? Do they affirm it will be on on earth, or in heaven?" Boa and Bowman point to the language of the new heavens and new earth from Isaiah 65-66 and used in 2 Peter 3:13. The description of the new heaven and new earth in Rev. 21 has the new Jerusalem coming down out of heaven with an announcement that "the dwelling place of God is with man." Furthermore, the man Jesus currently exists bodily in heaven. The barrier between heaven as the abode of spirit beings and earth as the abode of material beings is destined to be erased. Ultimately, heaven and earth will be one, so where is the fundamental difference among those who say we will end up in heaven and those who say we will be on earth?
But surely, you might say, the Scriptures must be fulfilled such as Num. 14:21, "All the earth will be filled with the glory of the Lord." Boa and Bowman write of two views on the destiny of this earth, which he calls the 'Renewal' view and the 'Replacement' view. In the Renewal view, this present earth will be restored and renewed, but will still be the same earth. In the Replacement view, this present earth will be annihilated and a new one created.
Boa and Bowman rightly stress need to balance the two. There are many scriptures which speak of renewal, such as "the times of refreshing" and "restoring of all things" (Acts 3:19-20). On the other hand, the picture of the physical world's fiery destruction painted in 2 Pet. 3:10-12 is quite complete. A balanced view affirms that while the changes to the earth will be so drastic that it could practically be described as a replacement, there must be some measure of continuity between the present earth and the new earth, otherwise it is not really the earth, and the promises concerning the earth's restoration have not been fulfilled. N.T. Wright draws out the importance of this continuity, applying Paul's words from 1 Cor. 15:58:
"You are not oiling the wheels of a machine that's about to fall over a cliff. You are not restoring a great painting that is shortly going to be thrown on the fire. You are not planting roses in a garden that is about to be dug up for a building site. You are -- strange though it may seem, almost as hard to believe as the resurrection itself -- accomplishing something which will become, in due course, part of God's new world" (Surprised by Hope, pp. 219-220)
The important conclusion here is that whomever believes in resurrection to an eternal bodily existence shares the One Hope. Fundamentally, this hope is not altered whether one believes the dead are conscious or unconscious during the brief period before the resurrection. Fundamentally, this hope is not altered whether one believes the redeemed will inhabit heaven or earth, since they will be one. We can all agree that there will be a new world where God and his people dwell. It will have some limited continuity with the present world but will be radically different.
We can and should continue to seek after the finer details from God's Word, while confessing that our knowledge is limited (1 Cor. 13:12). When differences in understanding these details arise, let us not quarrel and divide but unite around the new heavens and new earth, "the hope laid up for us in heaven" (Col. 1:5).