As I'm lead to understand, heaven is a word that, naturally, means the sky. But what God does with the "land and sky/earth and heaven" is create a physical analogue of empirical reality and abstract reality. Empirical means, the reality perceived through the senses. The Bible uses words like earthly, carnal, worldly, fleshly, sensual, of men. Abstract means reality perceived through the mind. The Bible used words like heavenly, spiritually, of God. The realm of thought, and idea. Heaven and earth; immaterial and material.
So when we look at the earth, we see it as very solidly made, with angles and forms, very defined, very sensual, to be felt. This being the analogue for empirical. Then when we look at the sky, it's not well defined. It's wisps of nebulous vapors drifting along a canvas of blue. Very unearthly, and this is the analogue of abstract; the realm of thought and idea.
And so the kingdom of heaven is not a worldly or empirical kingdom, it is an abstract kingdom of the mind: a kingdom of understanding. This is why Jesus would say, the kingdom doesn't come with observation. You can't see it, or touch it; it's an abstract kingdom.
Likewise, heaven isn't something we literally go to, it is a state of mind, a state of understanding; a state of heart and mind which through proper understanding of the Word brings us into a close communion with the Spirit of God within us, and causes peace with that personal idea of God that exists in our mind. A person who is not correctly understanding the Word can have a very corrupt image of God in their mind that causes them torment and fear, as they await wrath to come, or, make themselves to feel worthless and no good. But with proper understanding of the Word, the mind can be cleansed from all impurity of thought toward the relation and communion with God.
So heaven is a destination for our mind and understanding. Coming out of the darkness of fear, and enmity with God, caused by a conscience convicted of sin through ignorance, and gradually gaining clearer understanding, and coming into a better relationship with God through the lamp of understanding, the light of the Word. Once we come to this place of soundness of understanding, we have entered the kingdom of heaven, and increase in understanding from there.
So I don't believe heaven is a place we go that is like, a secondary earth hidden away in some other carnal location; but heaven is in the mind, and is readily available to us right now. We can "go to heaven" without ever having left "the earth"
BUT, I'd be remiss in not saying that, I do believe there will be a time coming in which the minds of men will have sufficiently come far enough out of the darkness of ignorance and, being lead by those in the kingdom of heaven, the earth will become "heaven on earth", entailing all that comes with that (a resurrection of the dead, a removal of disease and poverty, creation of an Edenic environment). This to me is because, the earth reflects the heaven. The earth that we currently live in is reflecting the mind of man, but when the mind of material man begins to wax toward immaterial godly mentality, then the earth will reflect the mind of God.