The Architecture of the Heavens: The Second Day Text: Genesis 1:6-8
Introduction: A World of Distinctions
We continue our study in the first chapter of Genesis, the foundational chapter of all reality. Last time, we saw God create the universe out of nothing and then, on the first day, speak light into the darkness. That first act was an act of separation, dividing the light from the darkness. This sets the pattern for all of God's creative work. God is a God who makes distinctions. He is a God of order, and order requires boundaries, definitions, and separations. To create is to distinguish.
This is a truth that our modern world despises. We live in an age that is pathologically committed to blurring every line God has drawn. The world wants to erase the distinction between good and evil, calling evil good and good evil. It wants to erase the distinction between man and woman, a foundational creation ordinance. It wants to erase the distinction between the sacred and the profane, the true and the false, the beautiful and the grotesque. This is not progress; it is a regression. It is a deliberate attempt to de-create, to return the world to the state of tohu wa-bohu, formless and void. The spirit of the age is a spirit of chaos, a spirit of rebellion against the God who separates.
On the second day of creation, we see this divine principle of separation at work again, this time on a cosmic scale. God is not just making a point; He is building a house. He is the master architect, and on Day Two, He puts the roof on. He establishes the basic structure of the world in which we live, separating the waters below from the waters above. This act is not some quaint, pre-scientific myth that we must be embarrassed about. It is a profound statement about the nature of the world, the nature of God, and the nature of the life He calls us to live within it. It is a world of glorious and life-giving distinctions, established by the command of the sovereign God.
The Text
Then God said, "Let there be an expanse in the midst of the waters, and let it separate the waters from the waters."
So God made the expanse and separated the waters which were below the expanse from the waters which were above the expanse; and it was so.
And God called the expanse heaven. And there was evening and there was morning, a second day.
(Genesis 1:6-8 LSB)
The Divine Command and the Expanse (v. 6)
We begin with the divine command in verse 6:
"Then God said, 'Let there be an expanse in the midst of the waters, and let it separate the waters from the waters.'" (Genesis 1:6)
Once again, God speaks, and reality rearranges itself to obey. His word is potent, effective, and creative. He speaks to the unformed world, still covered in water, and commands a new structure into existence. The word here is "expanse," from the Hebrew `raqia`. Older translations used the word "firmament," which comes from the Latin `firmamentum`, suggesting something solid and firm. This has led to centuries of skeptics mocking the Bible for supposedly teaching that a solid dome covers the earth.
But the Hebrew word `raqia` comes from a root that means to spread out, to stretch, to hammer out. Think of a metalsmith hammering out a thin sheet of gold. It speaks of something stretched out over a vast area. What is this expanse? Verse 8 tells us plainly: God called the expanse "heaven." This is the atmosphere, the sky, the space above us. God is creating the space where the birds will fly and where the clouds will gather. He is constructing the arena for life.
The central purpose of this expanse is to "separate the waters from the waters." On Day One, the Spirit hovered over the face of the waters. The entire unformed globe was a sphere of water in the dark. Now, God drives a wedge into this watery mass. He is continuing the work of forming the `tohu`, giving structure to the formless. He is an architect, not a magician. He is building a habitable world step by step, and the first step in building a house after the foundation is laid is to put up the frame and the roof, to create a protected space within.
The Divine Work of Separation (v. 7)
Verse 7 describes the execution of the command:
"So God made the expanse and separated the waters which were below the expanse from the waters which were above the expanse; and it was so." (Genesis 1:7 LSB)
The text emphasizes that God Himself did the work. "God made the expanse." He is hands-on. He is the builder. And the result is a fundamental division in the cosmos. We now have two distinct bodies of water: the waters "below" and the waters "above."
The waters below are easy enough to identify. These are the waters that will be gathered together on Day Three to form the seas. They are the oceans, lakes, and rivers. But what are the "waters which were above the expanse?" This has been a point of much discussion.
One very plausible understanding is that this refers to a vapor canopy that surrounded the earth before the flood. This canopy of water vapor would have created a different atmospheric pressure and a greenhouse effect, resulting in a uniformly temperate global climate. It would have shielded the earth from harmful cosmic radiation, which would help to explain the immense lifespans of the patriarchs recorded later in Genesis. And, most significantly, it would provide a ready source for the torrential rains of the Noahic flood, when the "windows of heaven were opened" (Genesis 7:11). This is not a required doctrine, but it makes a great deal of sense of the biblical data, taking the text in its most straightforward sense.
Another view is that the waters above simply refer to the clouds and the moisture held in the atmosphere. And this is certainly true now. But regardless of the precise mechanics, the theological point is paramount. God is establishing order by separation. He is creating a stable, protected environment for the life He is about to create. He is separating the heavens from the earth, creating the two great realms of His cosmic temple. The heavens will be the realm from which He rules and sends blessings like rain, and the earth will be the realm of man's obedient labor.
The Divine Naming and the Second Day (v. 8)
In the final verse of our text, God names His creation and concludes the day's work.
"And God called the expanse heaven. And there was evening and there was morning, a second day." (Genesis 1:8 LSB)
As we noted on Day One, naming is an act of sovereignty. By calling the expanse "heaven," God is asserting His absolute lordship over it. We don't get to define what the heavens are for; God does. He made them, He owns them, and He names them. The heavens are not an empty, random void; they are a created thing with a God-given name and a God-given purpose, which Psalm 19 tells us is to "declare the glory of God."
Now, something interesting is missing here. On every other day of creation, with the exception of this one, we read the phrase, "And God saw that it was good." Why not here? Is the sky not good? Of course it is. The likely reason is that the work of separation begun on Day Two is not yet complete. The heavens have been separated from the waters, but the waters below are still a chaotic, uninhabitable deep. The work is unfinished. It is only on Day Three, when God separates the water from the dry land, that the work of forming this part of the world is complete, and so on that day, the declaration "it was good" appears twice (Gen. 1:10, 12). This shows us that God's work is a coherent whole. The goodness of one part is often only apparent when seen in relation to the next. It is all purposeful, all moving toward a goal.
And the day concludes, "And there was evening and there was morning, a second day." Again, the text insists on a literal, 24-hour day. This is the rhythm of God's work week, which becomes the pattern for our own. God is not being poetic here; He is being liturgical. He is establishing the very pattern of time, work, and rest that will govern His covenant people. To surrender this to the high priests of secular science and their demands for deep time is to surrender the authority of Scripture at the very first chapter.
The Gospel in the Heavens
The work of the second day is a picture of the gospel. Just as God created a space for life by separating the waters, so God in Christ creates a space for our spiritual life by an act of separation.
Through the cross, God established a firmament, an expanse, between the waters of His judgment below and the waters of His grace above. Jesus absorbed the flood of God's wrath against our sin so that we might live under the open heaven of God's favor. He is the one who separates us from condemnation. "There is therefore now no condemnation for those who are in Christ Jesus" (Romans 8:1).
Furthermore, this act of separation is what God does in our sanctification. When we are born again, we are brought out of the chaotic deep of our sin and placed in a new environment. God separates us unto Himself. He calls us to be a people of distinctions, to separate ourselves from the world's rebellion, to distinguish between truth and lies, holiness and sin. He is building a structure in our lives, making us habitable for the Holy Spirit.
Every time you look up at the sky, you are looking at the work of the second day. You are seeing a sermon preached in blue. It is a declaration of God's power to bring order out of chaos. It is a testament to His architectural wisdom. And it is a reminder that the same God who separated the waters and established the heavens is the one who has separated you from your sin and established you in His grace. He has named you His own, and He is fitting you for His glorious temple, a new heavens and a new earth, where all His work will finally be complete, and He will declare it all, and us with it, "very good."