I got summoned into this thread. As it happens I'm writing a book about heaven right now so I do know a bit about it.
Basically, Lohrenswald's interpretation is pretty close. In New Testament times, there was no generally agreed-on notion of life after death within Judaism. Some Jewish groups believed in it and some didn't. Those who did generally thought in terms of a future bodily resurrection. So for example, take Daniel 12:1-3:
Daniel 12:1-3 said:
At that time Michael, the great prince, the protector of your people, shall arise. There shall be a time of anguish, such as has never occurred since nations first came into existence. But at that time your people shall be delivered, everyone who is found written in the book. Many of those who sleep in the dust of the earth shall awake, some to everlasting life, and some to shame and everlasting contempt. Those who are wise shall shine like the brightness of the sky, and those who lead many to righteousness, like the stars for ever and ever.
The Pharisees were one group who believed in this. In Matthew 22:23-33, Jesus is questioned about this topic as if he were a Pharisee, and interestingly he seems to accept the Pharisaic view there, or at least not distance himself from it. Paul, meanwhile, actually was a Pharisee, and teaches this idea more explicitly:
1 Thessalonians 4:13-18 said:
But we do not want you to be uninformed, brothers and sisters, about those who have died, so that you may not grieve as others do who have no hope. For since we believe that Jesus died and rose again, even so, through Jesus, God will bring with him those who have died. For this we declare to you by the word of the Lord, that we who are alive, who are left until the coming of the Lord, will by no means precede those who have died. For the Lord himself, with a cry of command, with the archangel's call and with the sound of God's trumpet, will descend from heaven, and the dead in Christ will rise first. Then we who are alive, who are left, will be caught up in the clouds together with them to meet the Lord in the air; and so we will be with the Lord for ever. Therefore encourage one another with these words.
You'll notice that Paul assumes in that passage that he and his readers will still be alive when this happens, because the early Christians thought that the end times were very nearly upon them. This is because they believed that Jesus' resurrection was basically the beginning of the general resurrection of the dead that would happen at the end of history. Paul is quite explicit about this, calling Christ's resurrection the "first fruits" - that is, the first ripe fruit of autumn that herald the coming harvest:
1 Corinthians 15:20-28 said:
But in fact Christ has been raised from the dead, the first fruits of those who have died. For since death came through a human being, the resurrection of the dead has also come through a human being; for as all die in Adam, so all will be made alive in Christ. But each in his own order: Christ the first fruits, then at his coming those who belong to Christ. Then comes the end, when he hands over the kingdom to God the Father, after he has destroyed every ruler and every authority and power. For he must reign until he has put all his enemies under his feet. The last enemy to be destroyed is death. For "God has put all things under his feet." But when it says "All things are put in subjection", it is plain that this does not include the one who put all things in subjection under him. When all things are subjected to him, then the Son himself will also be subjected to the one who put all things in subjection under him, so that God may be all in all.
And there are similar ideas in other, non-Pauline parts of the New Testament. In Matthew 25:31-46, we are told that the Son of Man will judge the nations at the end of time according to their works, and in Revelation 20:11-15 the same idea recurs, with the added detail that this includes those who have died:
Revelation 20:11-21:1 said:
Then I saw a great white throne and the one who sat on it; the earth and the heaven fled from his presence, and no place was found for them. And I saw the dead, great and small, standing before the throne, and books were opened. Also another book was opened, the book of life. And the dead were judged according to their works, as recorded in the books. And the sea gave up the dead that were in it, Death and Hades gave up the dead that were in them, and all were judged according to what they had done. Then Death and Hades were thrown into the lake of fire. This is the second death, the lake of fire; and anyone whose name was not found written in the book of life was thrown into the lake of fire. Then I saw a new heaven and a new earth; for the first heaven and the first earth had passed away, and the sea was no more.
So the general picture in the New Testament is that you die, and then at the end of time God will raise everyone from the dead and judge them, after which the blessed will pass into eternal life, and the damned will not.
However, this got complicated in early Christianity by getting mixed up with the idea that you have an immortal soul which survives the death of your body. This is not entirely alien to the Bible (2 Corinthians 4-5 and Luke 23:43 arguably hint at such an idea) but it's usually associated with Greek thought, both popular religion and Platonism. Christianity was certainly heavily influenced by Platonism and made a lot of this idea. So what we find by roughly the fourth century is a fairly standard amalgamation of these different ideas. Christians by this time generally believed that humans have an immaterial soul as well as a physical body. When you die, your soul leaves your body and it goes somewhere else. If you are good then it goes to heaven to be with God, and if you are not good then it doesn't. In Catholic theology, this is called the "particular judgement". In the fourteenth century, when there was a controversy about this, Pope Benedict XII described the state of the blessed in heaven like this:
Benedict XII said:
According to the general disposition of God, the souls of all the saints… and other faithful who died after receiving Christ's holy Baptism (provided they were not in need of purification when they died… or, if they then did need or will need some purification, when they have been purified after death)… already before they take up their bodies again and before the general judgment – and this since the Ascension of our Lord and Saviour Jesus Christ into heaven – have been, are and will be in heaven, in the heavenly Kingdom and celestial paradise with Christ, joined to the company of the holy angels. Since the Passion and death of our Lord Jesus Christ, these souls have seen and do see the divine essence with an intuitive vision, and even face to face, without the mediation of any creature.
However, at the end of time, God raises your body from the dead and your soul returns to it. Then you are judged, and after that you spend eternity either happily or unhappily, depending on the judgement, but you do so in your physical body, which is not subject to ageing or disease. The Catholic Catechism describes this state like this:
Catechism 1045 said:
For man, this consummation will be the final realization of the unity of the human race, which God willed from creation and of which the pilgrim Church has been “in the nature of sacrament”. Those who are united with Christ will form the community of the redeemed, “the holy city” of God, “the Bride, the wife of the Lamb”. She will not be wounded any longer by sin, stains, self-love, that destroy or wound the earthly community. The beatific vision, in which God opens himself in an inexhaustible way to the elect, will be the ever-flowing well-spring of happiness, peace, and mutual communion.
So you have a two-stage afterlife: a first, temporary, bodiless state in heaven, followed by the resurrection of the body and the general judgement, and then a permanent, embodied state in the new heavens and the new earth. (Of course, to make things complicated it was also believed that for most people, the first state isn't heaven at all but purgatory, where they go to be purified; only the saints go straight to heaven upon their deaths.)
Now at the Reformation this view was challenged. Some of the Protestant Reformers, notably Martin Luther himself and William Tyndale, promoted the idea of "soul sleep". On this view, there is no first stage to the afterlife at all. The soul either "sleeps" or ceases to exist entirely upon your death. So this was something of a return to the picture given in the New Testament, which is almost entirely focused on the future resurrection. This remained a common, but minority, view among Protestants for quite a long time.
Today, the trend has rather reversed itself, at least among ordinary believers, because we find that most Christians of whatever denomination think mostly in terms of "going to heaven" as what happens to you upon death, and have little consciousness of the notion of the resurrection of the body. The New Testament scholar and popular religious writer N.T. Wright has written at length about this state of affairs, which he thinks is pernicious and contrary to the Bible. Among academic theologians, as usual, the opposite view is more common, with the idea of the temporary "heaven" downplayed and much more emphasis on the future resurrection of the dead. This is in line with the common view of theologians - like philosophers - that the idea of an immortal soul is unbiblical and not rationally tenable today.
I only read the King James version of the bible as it is the closest thing in english to the original Hebrew and Greek translations.
It is not! You won't find biblical scholars using it. The NRSV is the standard scholarly translation used today. Plus of course, even if the King James version were perfectly accurate, the language it is written in is archaic modern English, not English as it is commonly spoken today. But the New Testament was not written in an archaic language, it was written in Koine Greek, which was a vulgar form of the language.