What is the firmament and the levels of heaven?

The firmament deals with the structure of the present heavens and earth, Genesis 2:1. In the present heavens and Earth there exists a three (3) heavens structure. Let's look at Genesis 1:6 again and more closely:

Gen.1:6-7 "And God said, Let there be a firmament in the midst of the waters, and let it divide the waters from the waters. And God made the firmament, and divided the waters which [were] under the firmament from the waters which [were] above the firmament: and it was so."

On the second day of the regeneration, the Lord God "divided" the waters (plural) of the great "deep" into two (2) parts, with a "firmament" in the midst. According to Genesis 1:10, both the waters that were upon the face of the earth and the waters which He placed above the firmament He called "Seas":

Gen.1:10 "And God called the dry [land] Earth; and the gathering together of the waters called he Seas: and God saw that [it was] good."

We know that the waters on the earth are called "Seas" in the bible, but there is also another "Sea" that is spoken of in the scriptures and that one is above the firmament. (Special Note: The word "Sea" is capitalized at Genesis 1:10 in the KJV Bible). But, exactly where is "ABOVE" the firmament? During the seven-days of the Genesis regeneration the Lord God defined three (3) heavens. The first heaven is the earth's atmosphere:

Gen.1:20 "And God said, Let the waters bring forth abundantly the moving creature that hath life, and fowl [that] may fly above the earth in the open firmament of heaven."

The second heaven is the vast expanse of the physical universe - outer space as we call it:

Gen.1:14 "And God said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days, and years:"

These two heavens constitute a continuum called the "firmament," and this firmament is collectively called "Heaven":

Gen.1:8 "And God called the firmament Heaven. And the evening and the morning were the second day."

The third heaven is above this upper "Sea," and this higher sea is below the throne of God:

Rev.4:6 "And before the throne there was a sea of glass like unto crystal: and in the midst of the throne, and round about the throne, were four beasts full of eyes before and behind."

This particular "Sea" is above the firmament (the known physical universe). It represents a firm and impassable barrier between the world of man (below) and the world of God (above).

John 8:22-23 "Then said the Jews, Will he kill himself? because he saith, Whither I go, ye cannot come. And he said unto them, Ye are from beneath; I am from above: ye are of this world; I am not of this world."

Here are some additional proof verses in the Bible which refer to this particular 'sea':

Psalms 148:4 "Praise him, ye heavens of heavens, and ye waters that [be] above the heavens."

This is the "sea" that John saw in his visions:

Rev.4:6 "And before the throne [there was] a sea of glass like unto crystal: and in the midst of the throne, and round about the throne, [were] four beasts full of eyes before and behind."

This "sea" of separation is a FIRM and impassable barrier between the world of man (below) and the world of God (above) and the only way through it is by the Lord Jesus Christ. This barrier structure can also be seen in the design of the tabernacle and the temple. It is represented by the veil that (without Christ) separates the holiest place (the holy of holies) from the inner and outer courts of the temple.

This now gives us a better understanding of what the Apostle Paul was talking about in the book of 2 Corinthians 12:2, where he speaks of a place called the "third heaven":

2 Cor.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."

Although the "third heaven" is not directly mentioned in the Genesis narrative, the established structure of all things is defined in Genesis 1 and, when understood, allows us to comprehend exactly where and what Paul was talking about when he mentions the "third heaven" in his letter. It also gives the reader a better understanding of John's vision in Revelation 4. Again, when the Lord God divided the waters He created a boundary which presently exists between the two lower heavens (which constitute the firmament) and the third heaven (where the throne of God is). That boundary is that "Sea," and again that "sea" is above the two lower heavens of the firmament.

The reason it appears like a smooth, crystal surface is because it is frozen:

Job 38:30 "The waters are hid as [with] a stone, and the face of the deep is frozen."

Exodus 24:10 "And they saw the God of Israel: and there was under his feet as it were a paved work of a sapphire stone, and as it were the body of heaven in his clearness."

It is also likened to glass:

Rev.15:2 "And I saw as it were a sea of glass mingled with fire: and them that had gotten the victory over the beast, and over his image, and over his mark, and over the number of his name, stand on the sea of glass, having the harps of God."

With this understanding of what exactly the firmament is and the structure of all things that God made during the seven days, many things that were previously obscure suddenly take on real meaning and enrich the reader's understanding.

In summary, here is the structure of the physical world as it now exists from the face of the earth upwards: