There are two possible answers to this question. Firstly, there is a physical heaven composed of our atmosphere, the air we breathe, the sky, and, further still, space, where we find the sun, the moon, the stars, and all the other galaxies and celestial bodies that comprise our universe. It is certainly of this physical heaven that David is speaking when he states: “The heavens are telling of the glory of God; and their expanse is declaring the work of his hands.” (Psalms 19:1). This is a heaven that we can see with our naked eye, contemplate and admire, and which is part of our world.
Secondly, there is the spiritual heaven, the realm in which spirits, God, Jesus and angels dwell, and which we, as earthly humans, can never have access to in our physical state. It is of this heaven that the Bible speaks in Isaiah 66:1: “Thus says the Lord, ‘Heaven is my throne, and the earth is my footstool. Where then is a house you could build me?’.” This heaven exists all around us but in another dimension, one we cannot apprehend mentally for we have never seen it or experienced it. Occasionally, angels (or spirit beings) from this realm have materialized and communicated with humans. The Bible records some of these instances.
Do humans go to this realm, the spiritual heaven, when they die? Hardly, for according to Ecclesiastes 3:19, 20: “the fate of the sons of men and the fate of beasts is the same. As one dies so dies the other; indeed, they all have the same breath and there is no advantage for man over beast…All go to the same place. All came from the dust and all return to the dust.” Will heaven be accessible to some humans? We answer, yes, because Jesus said: “I go to prepare a place for you … that where I am, there you may be also,” (John 14:2, 3,). These followers of Christ will be resurrected with a spirit body and live in the spiritual heavens. The majority of mankind, though, will be blessed to live in paradise on earth.