Often people are curious about the idea of heaven as a physical place.  Some people think of heaven as being above space or even beyond the universe. Some people think heaven is up above the clouds, sort of like the Greco-Roman mythology where Zeus and everybody can look down and get a clear shot with their lightning bolts.
In recent years it has been popular to think of heaven as existing on another plain of reality.  We could maybe think of heaven as being in a particular wormhole or an area of dark matter. There’s even this idea of finding heaven (like Shangri-La) and maybe being able to sneak in (an idea that has existed since then the dawn of religion).
In scripture Heaven is described  as including peaceful conditions on a new Earth governed by the Messianic-King wherein we will all experience bodily perfection (no hunger, thirst, death, or sickness) and use of a pure language.
C. S. Lewis’ book The Great Divorce talks about heaven being a place where you arrive upon a magical school bus.  In that heaven, everything hurts to touch because it is so real, where the arrivees are themselves only shadows of who they will become.  People show up comprised of half-vapor.  Their feet are torn apart as they try to walk on the blades of grass because they aren’t capable of interacting fully with reality.  They are given angelic guides, and they get to communicate with animals.  They find out that heaven itself is a journey, and that they have to ascend a great mountain to reach God.
Even though it is fictional, I think this is a great picture of what heaven might be like.  If you care to keep reading, you’ll see that Lewis also speculates about hell.  In the midst of this journey the newcomer’s angelic guide kneels down in the grass and picks apart two blades and says, “I think that’s hell down there but I can’t be sure.”  For Lewis, hell is insignificant in comparison to heaven.  It is a big emptiness where everyone who is there has chosen to be there by refusing again and again to get on God’s magical school bus (regularly God sends the magical school bus to hell and gives the invitation to anyone in hell who wants to leave and come to heaven).  Again, even though this seems like a terrible LSD flashback, Lewis is making a great theological point about our refusal to surrender control.  Consequently, hell is full of lonely people hating each other, consistently moving further and further into isolation .
C. S. Lewis’ speculation informs us. It allows us to move past our one-dimensional, simplistic understanding of heaven (being the happy place) and hell (the sad one).  I might also recommend the Richard Matheson book What Dreams May Come as a different, though equally provocative, speculation on the nature of the afterlife.
Ultimately, though, I think we’re wiser to focus on cooperating with God to achieve life “on Earth as it is in Heaven”.  If we focus on this, the afterlife will take care of itself. When the afterlife (or afterdeath) becomes our obsession (like it is for so many) and all we think about is getting people into heaven or out of hell, we treat them very differently.
We don’t treat people, culture, or the planet in a way that is synonymous with God’s ultimate purpose when we focus only on heaven/hell. His ultimate purpose shows the re-creation, the salvation of all people, the restoration of and the beauty of all creation, and we ought to work towards that redemption rather than merely individual conversions.
Our kingdom work has to be more than a sales pitch. Instead we have to be more concerned about living life on-Earth-as-it-is-in- Heaven right now.  That’s our orientation.  We believe we can participate in the life of heaven now.
What does that look like?  Brian McLaren’s talks about the Greek phase St. John used for eternal life literally meaning the “life of the ages.” Contrast the “life of the ages” with life as people are living it these days. Contrast the “life of the ages” with materialism, commercialism, fragmentation, brokenness, selfishness, and immorality. Is this what God has in mind?  What is eternal life supposed to be like when lived in service to the God who makes all things new? Who binds up the broken hearted?  Who gives freedom to the captive?  Who proclaims good news to the poor?  Who loves the Earth and everything in it?  Who is remaking it all? Who is giving new life to those who will accept it? This kind of life is radically different from the way people are living.  It is a life full and overflowing, a higher life centered in an interactive relationship with God through Jesus.
A God-breathed life is the conduit for the nervous system of our world, stemming and branching from the soul. Our soul is a barrier against reduction, against life reduced to mechanics and facts and the depersonalization of material quests.  When we live that soul-orientation instead of that self- orientation, then I think we are living and experiencing the Kingdom of God “on Earth as it is in Heaven.”
Len Sweet offers one metaphorical way of understanding the Kingdom of Heaven by suggested we consider “The Kingdom” as “The Presence of God.” He claims that whenever/wherever we experience The Presence of God – even as some kind of intangible feeling – that we are experiencing a foreshock of the Kingdom.
The Kingdom is the Presence.
In our regular lives, feeling/experiencing/welcoming God’s Presence gives us glimpses of what heaven will truly be like.  In simple ways we get moments of that.  You help someone; you feel that resonance inside you, that assurance, that confidence that you are doing a right thing.  You hurt someone; you feel the absence of that.  You experience the pain of that. Because, in heaven, we’ll be experiencing that sense of connectedness with our Creator all of the time.