For God, who said, "Let light shine out of darkness," made his light shine in our hearts to give us the light of the knowledge of the glory of God in the face of Christ (2 Cor 4:6).
The salvation we receive through Christ is a work of creation. The above scripture tells us that the same light that shone over the darkness at the time of creation in Genesis has shone in our hearts. Paul believed that the gospel he preached had that kind of creation power. In fact, Jesus said to Paul at the time of his conversion:
I will rescue you from your own people and from the Gentiles. I am sending you to them to open their eyes and turn them from darkness to light, and from the power of Satan to God, so that they may receive forgiveness of sins and a place among those who are sanctified by faith in me (Acts 26:18).
The following words are also found in his letter to the Colossians:
For he has rescued us from the dominion of darkness and brought us into the kingdom of the Son he loves, in whom we have redemption, the forgiveness of sins (Col 1:13-14).
This type of God’s creation, needless to say, is first seen at the beginning of the book of Genesis.
In the beginning God created the heavens and the earth.
Now the earth was formless and empty,
darkness was over the surface of the deep, and the Spirit of God was hovering over the waters.
And God said, "Let there be light," and there was light. God saw that the light was good, and he separated the light from the darkness.
God called the light "day," and the darkness he called "night."
And there was evening, and there was morning--the first day (Gen 1:1-5).
As for the same type of creation, John in the New Testament writes in the following way:
In the beginning was the Word,
and the Word was with God, and the Word was God.
He was with God in the beginning.
Through him all things were made;
without him nothing was made that has been made.
In him was life, and that life was the light of men.
The light shines in the darkness,
but the darkness has not understood it (John 1:1-5).
We need to keep in mind that creation not only occurred for this universe in a physical sense at the time it was created, but also occurs today for anyone who accepts the gospel of Jesus Christ. Do not limit yourself by thinking that God’s creation is only for physical things. He can, of course, creates things physically out of nothing, but he also creates you spiritually. Read, for instance, the following story as such creation—creation of God’s people:
Then the angel of God, who had been traveling in front of Israel's army, withdrew and went behind them. The pillar of cloud also moved from in front and stood behind them, coming between the armies of Egypt and Israel. And there was (the division of) the cloud and the darkness. And it (the cloud) lighted up the night; so neither went near the other all night long. Then Moses stretched out his hand over the sea, and all that night the Lord drove the sea back with a strong east wind and turned it into dry land. The waters were divided, and the Israelites went through the sea on dry ground, with a w (Exod 14:19-22, the translation of italicized part is mine).
This cloud was shining all the time, though it did no look shining during day due to the sunlight. The cloud was the light shining over the darkness of night. The Egyptians were chasing after the Israelites, but the cloud stood behind the Israelites to separate them from the Egyptians. Compare this story with that of Genesis 1. Note the way that the sea was divided by a wind (ruach in Hebrew meaning “spirit”).