I'm interested in the various opinions on here of Heaven and Hell, and what the Christian viewpoint is, is there a consensus?
For example - Heaven, is it an actual place, like a planet or is it something undefined,
In the most strict sense "the heavens" describes everything we see when we look up into the sky, it's where the moon, sun, and stars are located from an earth-bound observer. The ancient Hebrews conceived of God as being beyond or above the heavens, an attempt to speak of God as being bigger than and more than the celestial powers we see with our eyes (this was doubly important because Hebrew religion insisted that the worship of celestial powers was the worship of false gods, and that the true God could not be depicted as anything). So, for example we see Solomon's declaration concerning the Temple, "The heavens, not even the highest heavens, can contain You; how much less this house which I have built." Or elsewhere where the Psalmist writes, "The heavens are Your throne, and the earth Your footstool."
So there is this idea that God is always beyond and above the observable world, and so the idea of the "highest heavens" or even just shorthand "the heavens" can be used to refer to God's power and authority in some fashion. By the time we get to the first century we can see that "Heaven" is used somewhat euphemistically for God; in Mark and Luke Jesus proclaims "the kingdom of God" whereas in Matthew the parallels read "kingdom of heaven"--neither refers to a location, the concept of "kingdom" here is not a nation or place, but to the royal power and authority of the one who rules. It can also be translated as "the reign of God", which isn't a place anyone goes, but is the reality of God's reign breaking into the world through the Person and work of Jesus, in Luke Jesus says to a group of hostile religious leaders, "the kingdom does not come with observation...instead the kingdom is in your midst", it is Jesus who as the Messiah is the manifest reality of God-as-king.
Further "Heaven" has from here also been understood to be in some sense "where God is" but thinking of "Heaven" as this place where God dwells is the wrong way to understand that language; it instead means to be with God, perhaps in ways we cannot understand. It's important to keep in mind that in Christian theology God is everywhere, there is no
where where God is not.
Finally the closest we have to an idea of "going to heaven" as something that happens after we die comes from a single statement made by St. Paul where he says "to be absent from the body and present with the Lord", that between death and resurrection we are in the presence of Christ. Whatever that means; but this is essentially the basis for conceiving of "life after death" as "going to heaven", it is about being with God in a state of waiting until the resurrection. Which gets us to your next question:
and is eternal life in a body such as we have now or is it purely as a spirit/ soul?
The historic, normative, and orthodox Christian teaching is that at the conclusion of history, when Christ returns in glory, the dead will be raised bodily. You'll note that in my above statements about heaven I mentioned "between death and resurrection", that's because the whole idea of "going to heaven" is about what we call the intermediate state. "Heaven" is the waiting room, a foretaste of what will be forever. Because in traditional Christian theology we look forward to the renewal and restoration of the whole of creation, "a new heavens and a new earth" where God has made all things new. And so our eternal hope is a resurrected, bodily existence, right here on God's green earth.
There are two equally problematic ideas that have arisen in modern times due to a lack of proper theological information within a number of churches, even mainstream traditional churches.
1. The first problematic idea is that the Christian hope is to go to this "place called heaven" where we will float around as disembodied spirits, on fluffy clouds, strumming harps etc. That's what we might call modern popular religion, but it has no basis in the official teachings and creeds of any of the historic churches (Catholic, Orthodox, or Protestant).
2. The second problematic idea is much like the first, only it says that when we get to "heaven" we'll be given these new spiritual bodies where we'll get to trot around on streets of gold.
The problem with both is that it ignores the fundamental teachings of the Christian faith: That there will be a resurrection of the body and eternal life in the age to come, not in some distant blissfuly by-and-by, but in God's renewed, made whole, creation--
right here.
So, yes, you'll absolutely find some Christians (wrongly) assert one of those two ideas, but such does not represent what Christians have historically believed for the last two thousand years, consider just for example the Apostles Creed which is read every worship service in Catholic, Lutheran, Anglican, and many other Protestant churches which says, "I believe ... in the resurrection of the body, and the life everlasting." The original Latin here reads
carnis resurrectionem, literally "resurrection of flesh"
Is life eternal really life eternal?, I mean eternity is a very long time and we cannot conceptualise it, what do Christians think is meant by Life Eternal?
Immortal and incorruptible, unceasing and unending.
I need to go grab a bite to eat, but I'll come back later to try and tackle Hell, which will be a much more complicated topic to engage. Largely because Christianity has been far less dogmatic in its treatment on hell.
-CryptoLutheran