The Bible speaks of three heavens: the first heaven, the second heaven, and the third heaven. We know that there are three heavens because the apostle Paul said in II Corinthians 12:2,
“I knew a man in Christ above fourteen years ago, (whether in the body, I cannot tell; or whether out of the body, I cannot tell: God knoweth;) such an one caught up to the third heaven.”
If there is a “third heaven,” then there must be a “first heaven” and a “second heaven.” There couldn't be a “third heaven” if there wasn't a “first heaven” and a “second heaven.”
The first heaven is the atmosphere around our earth. It extends from the surface of the earth to about 100 kilometers above the earth (where the Karman line is). This includes the troposphere (10 kilometers), the stratosphere (40 kilometers), the mesosphere (35 kilometers), and the first 15 kilometers of the thermosphere. This is where the birds fly, airplanes fly, the clouds are, weather balloons are, etc.
The second heaven is what we call “outer space” or “space” for short. It begins where the earth's atmosphere ends (at about 100 kilometers above the earth, where the Karman line is) and extends outward. This is where our moon is, the planets are, the stars are, etc.
The third heaven is, obviously, where God is. This is where the apostle Paul was “caught up to.” And even though the third heaven has always existed—just like God has always existed—it has not always been called “the third heaven.” It only began being called “the third heaven” when “God created the heavens (the first heaven and the second heaven) and the earth” (Genesis 1:1) about 4½ billion years ago.
The Bible says that Heaven (the third heaven) is north of the earth (Psalm 48:2; 75:6–7; Isaiah 14:13). It is not visible to us because it is in the spiritual realm.
Whenever “Heaven” is referred to, and it is clear from the context that “the third heaven” is being referred to, the word “Heaven” should be capitalized because the word “Heaven” is a proper noun that is the name of a specific place (the third heaven).
But if the Bible says “heaven” or “heavens” and it is clear from the context that it is not specifically talking about “the third heaven,” the words “heaven” or “heavens” are being used generically and should not be capitalized.
An example of this is in II Kings 2:11 where Elijah was taken up into the sky by a chariot of fire and horses of fire by a whirlwind. The KJV and many other translations say that Elijah was taken into “heaven.” But some translations say, and the literal Hebrew translation is, “the heavens.” This is the same Hebrew word here that is used in Genesis 1:1 and many other places in the Old Testament. The word is “šÄmayim” (shaw-MAH-yimm). It is what is called in the Hebrew a “dual” word. It means “two heavens.”
We know that Elijah was not taken up into Heaven (the third heaven, where God lives), because before Jesus came and lived and died and rose again from the dead, no one could go to Heaven (the third heaven, where God lives) because no one could get born again and become righteous by nature. And only people who are righteous by nature, and have no sin nature in them, can get into Heaven. Jesus said when He was on earth before He died and rose again from the dead (before anybody could get born again),
“And no man hath ascended up to Heaven, but He that came down from Heaven, even the Son of man which is in Heaven” (John 3:13).
So instead, when the Old Testament saints died (or when they were taken by the Lord without dying, as in the cases of Enoch (Genesis 5:24) and Elijah (II Kings 2:11)), they went down into the heart of the earth to a place of paradise called “Abraham's Bosom” (Luke 16:19–31). Luke 16:19–31 is the true story—not a parable—of a rich man and a man named “Lazarus.” Once Jesus was born again and rose from the dead, the people in Abraham's Bosom were born again and then were taken to Heaven (the third heaven, where God lives) by Jesus (Ephesians 4:8–10).
(more to come)