Douglas F. Kelly compares God's ability to speak light into the dark human soul and make it reborn to God's speaking light into existence.

The Sending Forth of Light

The Ancient of Days (William Blake, 1794)

A third divine action occurred on the first day of creation: 'And God said, Let there be light: and there was light' (Gen 1:3).  Elsewhere in Scripture we learn that God Himself is uncreated light (e.g. John 8:12; 1 John 1:5; Revelation 21:23; 22:5).  But now the One who is light and 'swells in light inapproachable' (1 Timothy 6:16) commands forth created light into the darkness of t he yet unformed earth.

The mighty hand of God shaping and organizing the dark, watery mass in the direction of a beautiful garden

The Creation – Bible Historiale (c. 1411)

The speaking into existence of the created light is the first of a series of three separations accomplished by the Creator which were essential to make the chaos into a cosmos.  On Day One, light separates day and night; on Day Two the 'firmament' separates the upper waters from the earth, constituting an atmosphere or 'breathing space'; and on Day Three, the waters below the heavens are collected into seas, and thus separated from the dry land.  These three separations show the mighty hand of God shaping and organizing the dark, watery mass in the direction of a beautiful garden; a fit and lovely swelling place for plants, animals, and humankind.

The Genesis Flood: The Biblical Record and its Scientific Implications is a 1961 book by young Earth creationists John C. Whitcomb and Henry M. Morris that, according to Ronald Numbers, elevated young Earth creationism "to a position of fundamentalist orthodoxy."

Henry Morris would seem to be right in suggesting that with the coming of the light on the first day, '... there was established a cyclical succession of days and nights -- periods of light and periods of darkness.' He adds:

'Such a cyclical light-dark arrangement clearly means that the earth was now rotating on its axis and that there was a source of light on one side of the earth corresponding to the sun, even though the sun was not yet made' (Genesis 1:16).  [Since] '... the presence of visible light waves necessarily involves the entire electromagnetic spectrum … setting the electromagnetic forces into operation completed the energizing of the physical cosmos ...'

The biblical view of reality never separates God

from the elements He created and controls

Depiction of Genesis 1:2 by Wenceslaus Hollar

The question of how there was light on earth before the sun was created (on Day Four -- Genesis 1:14) brings us back to the biblical view of reality, which never separates in deistic fashion God from the elements He created and controls.  We are simply not told what the source of light was before the sun was placed in the sky.  All the text says is that God spoke and the light was there.

Reality is untrammeled by man-centered assumptions

which would bring God down to our finite level

Creation of Light, by Gustave Doré

John Calvin's admonition should be taken to heart if we wish to grasp reality as it is, untrammeled by man-centered assumptions which would bring God down to our finite level:

Therefore the Lord by the very order of the creation, bears witness that he holds in his hand the light, which he is able to impart to us without the sun and moon.

Should this be thought difficult for One who is light?

The first time God speaks in Scripture, light appears and a person whose life is darkened and condemned by sin, becomes 'light in the Lord'

The Conversion of Saul on the road to Damascus as painted by Michelangelo

It is significant that the first time God speaks in Scripture, light appears.  According to Psalm 119:130, 'The entrance of they words giveth light'.  It was so in the old, original creation, and the apostle Paul tells us that something similar happens in 'the new creation', when a person whose life is darkened and condemned by sin, becomes 'light in the Lord' (Ephesians 5:8).  In 2 Corinthians 4:6, he quotes directly from Genesis 1:3: 'For God, who commanded the light to shine out of darkness, hath shined in our hearts, to give the light of the knowledge of the glory of God in the face of Jesus Christ.'  Such an enlightening of the human personality as it is enabled to see who the Son of God really is, constitutes nothing less than 'a new creation' (2 Corinthians 5:17).

Only someone so great as the mighty Creator God could speak light into the darkness of the primeval earth and able to speak light into the dark human soul making the chaos of sin into the cosmos of a new creation in Christ

Separation of light and darkness on the first day of creation, from the Sistine Chapel ceiling by Michelangelo

The analogy between the two creations is fascinating.  Only someone so great as the mighty Creator God could speak light into the darkness of the primeval earth in the first creation.  Only He -- the Almighty Word, the uncreated Light -- is able to speak light into the dark human soul of the smallest child or greatest king, and thus bring it into a new birth (see John chapter three and Jeremiah chapter thirty-one), making the chaos of sin into the cosmos of a new creation in Christ.  And in both cases, the instrument of transforming enlightenment is His spoke word, which never 'returns to him void' (Isaiah 55:11).  His 'fiat' command (as the Latin translation of the Bible phrases 'let there be') always finds fulfillment.  Whenever God commands light into the dark, formless elements of earth or into the spiritually blind energies of self-defeating human psychology, light appears in both scenes and beauty replaces disorder.

Source: Kelly, Douglas F.  Creation and Change -- Genesis 1.1 - 2.4 in the Light of Changing Scientific Paradigms.  Scotland, U.K.: Christian Focus Publications, 2017, pages 108-110.

Records from the King of Assyria recovered in the 19th and 20th centuries back up the explanation in the Old Testament of the exile from Judah to Babylon

Explaining the Exile from Judah to Babylon

for later Generations

James Tissot, The Flight of the Prisoners.

… The prediction of the future was necessary to explain the exile.  Without the messages of the prophets, the people might have concluded that the gods of the nations were more powerful than Yahweh, which was why they had been captured and taken away into exile by these nations.  This wrong belief is clearly illustrated in Isaiah 36:16-20 and 37:1-13.  During that time period, the Assyrians attacked Judah and Jerusalem and conquered most of the cities in Judah.  Today we have the documents and records from the King of Assyria, which were uncovered by archaeologists. 

The Annals of Sennacherib were recorded

on a clay prism

The Annals of Sennacherib were recorded on a clay prism on which the Assyrian king states:

As for Hezekiah, the Judean, I besieged forty-six of his fortified walled cities and surrounding smaller towns, which were without number.  Using packed-down ramps and applying battering rams, infantry attacks by mines, breeches and siege machines, I conquered [them].  I took out 200,150 people, young and old, male and female, horses, mules, donkeys, camels, cattle, and sheep.  He himself I locked up in Jerusalem, his royal city, like a bird in a cage.  I surrounded him with earthworks and made it unthinkable for him to exit by the city gate. (Mordecai Cogan, "Sennacherib's Siege of Jerusalem (2.11B)," in The Context of Scripture, ed. William W. Hallo and K. Lawson Younger Jr. (Leiden, NL: Brill, 2003), 2:303.)

The gods of Assyria are bigger and better than Yahweh,

Rabshakeh claims

Assyrian soldier, using a dagger, about to behead a prisoner from the city of Lachish. Detail of a wall relief dating back to the reign of Sennacherib, 700–692 BC. From Nineveh, Iraq, currently housed in the British Museum

In Isaiah 36 and 37 the commander general of the Assyrian army, Rabshakeh, gives a message to the people in Jerusalem telling them not to trust in Yahweh and not to let King Hezekiah deceive them by telling them that Yahweh will deliver Jerusalem.  The Rabshakeh gives a list of countries that Assyria has conquered and demonstrates that the gods of those conquered places had been unable to deliver their people.  Then Rabshakeh insults and mocks Yahweh, saying that he is no different from the gods of the conquered nations and will not be able to deliver Judah and Jerusalem.  The gods of Assyria are bigger and better than Yahweh, Rabshakeh claims.  According to Deuteronomy 32:27, this is exactly what Yahweh said the enemies would think.

Imagine undertaking the journey on foot,

in chains for weeks, perhaps months,

and finally arriving in Babylon

in a land far away from home

Illustration from the Nuremberg Chronicle of the destruction of Jerusalem under the Babylonian rule

The reconstruction of the Ishtar Gate in the Pergamon Museum in Berlin

Apart from the prophetic word, imagine what the people of Jerusalem would have thought when the Babylonians came and conquered the city and razed it to the ground, exiling the citizens to Babylon.  Imagine undertaking the journey on foot, in chains for weeks, perhaps months, and finally arriving in Babylon in a land far away from home.  Imagine walking down a corridor of high walls, beautifully decorated, and arriving at the massive Ishtar Gate of the city of Babylon.  Archeologists have reconstructed this gate, and it is displayed in a museum in Berlin.  Even today, simply viewing the reconstruction is an overwhelming experience.  Were it not for the prophetic word, the people of Judah and Jerusalem would surely have concluded: "Now we know why the Babylonians conquered us.  It is because the gods of Babylon are bigger and more powerful than Yahweh."

They were conquered for only one reason:

they had violated the covenant

Destruction of the Temple of Jerusalem (1867 painting by Francesco Hayez)

Such a conclusion, of course, would have been utterly wrong.  They were conquered for only one reason: they had violated the covenant, and the covenant curses of Deuteronomy 28 had come upon them.  God had promised that he would send enemies and kick them out of their land, and he had finally kept his word and done it.  God brought the Assyrians and the Babylonians against his own people for violating the covenant.  It was necessary, then, for the predictions of Isaiah, Jeremiah, and Ezekiel to be written down so that when those events occurred, the people of Israel would draw the right conclusions.

Source: Gentry, Peter J. How to Read and Understand the Biblical Prophets. Wheaton, IL: Crossway, 2017.