This article looks at the Greek words Christ uses that are translated as the "Earth," the "World," and "Heaven." The concept of "heaven" is also covered in this article about the kingdom of heaven. In the tradition of Christ, let us start with earthly things and progress to heavenly things.
The World and the Earth
Christ uses two different Greek terms to describe the place where humanity lives. On describes human society, the other describes the planet. Both of these words only occur in the singular. Sometimes these words appear with an article "the", but sometimes they don't. Unfortunately, Biblical translation adds articles or subtracts them regardless of the Greek. Those distinctions are not currently covered here, though they are being explored for a future addition to this article.
The most common one is kosmos. It is usually translated as "the world" in the KJV and most other English translations. The Greek kosmos is very different than the English word, cosmos. The English word refers to the universe, but the Greek word does not describe Carl Sagan's cosmos.
In Greek, cosmos means "the world," but it specifically means the world of people. It means society, civilization, and the political powers and divisions of that world. This is the kosmos of the English word, cosmopolitan, which combines the kosmos with the polis, the Greek word meaning "city."
Christ uses the word in the Greek sense, the world of people. More to the point, the kosmos is the man-made world. It includes not only the physical products, our cities, and our tools, but also our man-made culture: our ideas, our sciences, and so on. Christ tells those who challenge him, "You are of the world; I am not of the world (Jhn 8:23)." He says this challenging the way they think and see the world, that is, their cultural and intellectual viewpoint.
Christ also uses another word to describe our planet. That word ge. This word is usually translated as "the earth" in the KJV Bible but occasionally as "the land" and "the ground." Ge is the God-made world, the planet. The world of nature. Earth in the sense of "dirt" and growing things.
The two terms, the world and the earth, are often interchangeable in English. They are not interchangeable in the Greek of Christ's words. Most translation respect this fact. When you see the word "world" in any mainstream translation, the Greek source is kosmos . When you see "earth" or "Earth," the source is ge.
What Christ Says About the World and the Earth
Christ says very different things when talking about kosmos and talking about ge. He never says that he came to earth. He always says that he came into the world. He speaks in the world (Jhn 16:28 et al). It is the world into which children are born (Jhn 16:21). He and his followers are the light of the world (Jhn 12:46 and Mat 5:14). It is the world that rejoices (Jhn 16:20) and hates (Jhn 7:7). Every idea he expresses about society, the good and the bad, he attributes to "the world," that is, the kosmos.
Christ says must less about the planet, ge. He says that the meek shall inherit the earth. Whenever he talks about "heaven" in relationship to the planet, he uses ge. When he talked about the earth passing away, he talks about ge. Christ will be lifted up from the planet, not human society (Jhn 12:32). This is contrasted with a seed the must fall into the planet and die to produce fruit (Jhn 12:24).
To see a clear contrast between his two use of the term, look at Mat 5:13. where he talks about "the salt of the earth" and the following verse, Mat 5:14, where he talk about "the light of the world." In both, he is addressing his followers. In the first, he is talking about their natural wit. In the second, he is talking about what they know that human society doesn't know.
This brings us to a discussion of where "heaven" fits into this picture.
The Meaning of "Heaven"
Christ most commonly uses the Greek word translated as "heaven", that is, ouranos, in the phrase "heaven and earth." He never pairs "heaven" with "the world", that is, kosmos. However, the word translated as "heaven" actually means "sky." The same word is translated as "sky", for example, when referring to birds. This word is used in the singular and plural, where the singular seems to refer to our planet's sky while the plural seems to refer to the universe. In referring to the kingdom of heaven or his Father in heaven, the plural, "skies" is most often used. When referring to the vault of the sky, the singular. "sky", is most often used. See this article on the kingdom of heaven.
This same word, ouranos, also means a "chamber pot." So there is always something humorous about describing something as "the kingdom of heaven" since it also means "the kingdom of the piss pot." This meaning comes from the Greek word oureter, the source of our word ureter.
Heaven and earth together are the "natural" order, that is, what is created by God. Heaven and earth are, in a sense, the opposite of "the world" since the world is what is man-made.
Another perhaps even common phrase using the term "heaven" is the "kingdom of heaven," which is discussed in this article along with related ideas.
The biggest problem is that when we hear the word "heaven" today, we have a set of images that have nothing to do with the way Christ meant the word. We see clouds, angels with wings, streets of gold, and pearly gates. Much of this is from childhood stories, and, unfortunately, at least some of it is borrowed from stories taken from other religions.
To get those images out of our heads, it may be best to think of "heaven" as simply "that which is beyond earth." However, this loses some of the sense of "great height" that we get from the Greek idea of "heaven" and up in the sky. This "height" is very important to Christ in a philosophical sense and for much of his wordplay. Heaven is the realm of the highest concepts. It is beyond earth both in the sense of being physically out of reach and in the sense of being higher in the sense of superior.
Christ often describes that Father as "in heaven," for example in Mat 5:45. We can read the as "in the universe", "beyond the earth," or "in the heights." Though often translated as "in heaven" in the English NT, Christ also describes the Father in Greek as "of heaven" or "heavenly" where "heaven" is used like an adjective. This can be translated as "the universal Father", "the Father beyond earth," or "the highest Father.
Christ uses the plural "Father in the heavens" perhaps more often than he does the singular (Mat 6:1). This also almost always changed in translation (not here of course). The plural "heavens' works if we think of the word as meaning "that beyond earth." There are, after all, many places beyond earth. It also works with the concept of highest, since there are many different types of "height," at least conceptually. It works less well with the idea of "universe" unless we want to think that Christ was an early proponent of the multi-universe theories.
Though Christ refers to the Father as "in" heaven, no one takes this to mean that the Father is physically contained within the universe or any group of universes. The sense is that the Father is active within the universe. "Inhabiting" the highest realms beyond earth.
"Heaven" and "Earth"
This same divine power connects heaven and earth. This is stated explicitly in Mat 28:18. This also is the opposite of powers of "the world" where "the prince of the world" plays a role.
The end of heaven and earth are also connected. Christ always discusses them "passing away" together (Mat 5:18, Mat 24:35). The term "pass away," may not mean "come to an end", but it is clearly a change that can affect both heaven and earth. That connection seems to indicate that they both exist within time. (Note: Christ never talks about "the world," the kosmos, "passing away" but seems to discuss its end in terms of "the end of an era," where era is aeon in Greek.)
This idea that both heaven and earth exist in time is supported by the Mat 6:10, the line from the Lord's Prayer that is translated as "Your will be done on earth as it is in heaven." This translation indicates that activities should be performed on earth as they are performed in heaven. However, the original Greek does not say this. The word translated as "done" is ginomai, which is the Greek verb of becoming, that is, changing into a new state. The word translated as "as" is the conjunction "and". The phrase says something closer to "Your will is coming into begin in heaven and on earth." Interestingly, the order "heaven" and "earth" are reversed in the translation to make the "as" comparison work. While the Greek word translated as "as" is usually translated as "and." It can be translated into "as" but only when are comparison is being made.
Identical phrases are used in Mat 28:18, the reference to the power of heaven and earth, and in Mat 6:10, the line from the Lord's prayer. Again, this difference is obscured in translation, but it may be relevant. The phrase, translated directly into English is "in heaven and upon the earth." Two different prepositions are used. They indicate that heaven is something you are in while the earth is something you are on. In the case of the earth, this is certainly easy to understand, since we are one the planet, the land, and the ground. In the case of "heaven," however, we can only speculate. Heaven may be a state of mind or state of becoming. It may also simple be the "kingdom" that is discussed in the article mentioned above.
It is important to note that Christ doesn't refer to "heaven" as the location of "eternal life." Christ mentions eternal life in many forms but he never connects it to "heaven" in the same way that he connects God to "heaven." This is done naturally today, but clearly, the ideas were not as connected in Christ's words. The closest that he comes to connecting "heaven" to the afterlife are in statements like Mat 5:12,where he discusses a "reward" or "payoff" in heaven. In all such statements about treasure in "heaven," it is described as a storage place for things we will enjoy. Supporting the idea that heaven is a different state of being, we go back to the idea of time passing in becoming. If time exists in "heaven," it exists in a different form than it does on earth. In Mat 6:19, Christ says the treasures on earth decay. Then in Mat 6:20, says that things do not decay in heaven. This indicates a different type of "becoming," one which changes perhaps only for the better.
The Realms of Water and Spirit
From the perspective of translating hundreds of verses regarding heaven and earth, a sense emerges that Christ does not see his role as describing "heavenly" things Jhn 3:12. Interestingly, he does this after discussing being born of water and the spirit, both of which he describes as "earthly" things not "heavenly" ones. So our world is a home for both the physical world of flesh, which is born from the water of the womb. That flesh or water, then, is a home for the spirit.
In Greek, the verse, Mat 4:19 "Follow me, and I will make you fishers of men," gives us an interesting perspective on Christ's view. This view, however, is lost in translation. In Greek, the word translated as "fishers" is based on the Greek word for the sun, helios." In English, we talk about "landing" a fish. In Greek, the ideas was "sunning" a fish, that is, bringing it into the sun from the depths of the water.
The analogy offers a powerful perspective about Christ's view of heaven and earth. Our world is like being deep in the water, where there is little light and everything is in shadows. Everything is constantly moving. Heaven, or what is above this world, is a world of light, where there is solid ground. A fish in the ocean doesn't know that the world above exists. It knows only water. Christ wants us to know that there is another level of existence. This is not just a place we can be, but a way in which we can view the universe. Our view of the universe from under water is always murky. Our view of the universe from the perspective of what is above and beyond is much clearer and more stable.