The Bible is one large inclusion. An inclusio is a Biblical literary device that brackets information around similar thoughts or and ideas. Whatever information that is in between the brackets is to be understood by what brackets it. Confused yet? Let me try to explain it using the Bible.
The Bible begins this way:
1 In the beginning, God created the heavens and the earth. 2 The earth was without form and void, and darkness was over the face of the deep. And the Spirit of God was hovering over the face of the waters. 3 And God said, “Let there be light,” and there was light Genesis 1:1-3)
The Bible ends like this: "And night will be no more. They will need no light of lamp or sun, for the Lord God will be their light, and they will reign forever and ever (Revelation 22:5)
If you notice the underlined portion of each scripture reference what you see is the dual theme of light and darkness. These words represent the inclusio for the entire Bible. Therefore, one is right to conclude that the entirety of the Bible is about light and darkness. More specifically, the Bible is about the battle between the light and the darkness and so, the big picture message of the Bible is how God overcomes darkness with light. That is the Bible in a sentence. Yet, there is more here.
We see this understanding played out in significant aspects of the Bible' narrative. Obviously, Genesis 1:3 shows that God has the power to speak into and over darkness to expel its presence with light. This points to the victory that the Bible will prove repeatedly. In another book that begins like Genesis we see the same reality. John begins his gospel with the same three words of Genesis 1: "In the beginning" (John 1:1). This is not an accident but a powerful pointing back to the beginning of all things to show that, in Christ, there is a new beginning dawning. We know this because John will remind us of the theme of light and darkness of Genesis 1, but reframe it in a Christological way:
1 In the beginning was the Word, and the Word was with God, and the Word was God. 2 He was
in the beginning with God. 3 All things were made through him, and without him was not any
thing made that was made. 4 In him was life, and the life was the light of men. 5 The light shines
in the darkness, and the darkness has not overcome it (John 1:1–5).
Light and darkness, as John sees them, are no longer representative of their physical presence. Something more is to be understood. They represent the conquering of righteousness (light) over unrighteousness (darkness). We are taught that the overcoming of darkness by the speaking of light in Genesis 1 was a foreshadowing of what God would accomplish through Christ (John 1:5) over the sin the was born out of the Garden.
From Genesis 3 on what we witness is the constant battle of light with darkness. The Old Testament is the story of the progressive nature of sin and the many battles of light against its encroachment. Sin never won because the temple sacrifices atoned for sin. The problem was that the guilt of man's sin could not be adequately defeated by the blood of animals since "it is impossible for the blood of bulls and goats to take away sins (Hebrews 10:4). Darkness did not win, but it was not stopped...until Christ appeared, as the Light of the World (John 8:12) to take away the sins of the world (John 1:29)
Jesus came to save, but salvation is achieved when the darkness of sin is overcome by the light of the gospel. Paul says "for at one time you were darkness, ... (Ephesians 5:8). Man, outside of Christ, does not simply walk in darkness but is darkness according to the Bible. This darkness is representative of our moral and intellectual depravity both of which are the consequence of the sin of Adam. Paul goes on to describe our new status because of Christ, "but now you are light in the Lord. Walk as children of light (Ephesians 5:8). In Christ we are new creatures, but this newness comes, not because we are better people but because of the light of the gospel that penetrates the darkness such that darkness has been overcome the light (John 1:5). Paul tells us this process of how this happens:
And even if our gospel is veiled, it is veiled to those who are perishing. In their case the god of
this world has blinded the minds of the unbelievers, to keep them from seeing the light of the
gospel of the glory of Christ, who is the image of God. For what we proclaim is not ourselves,
but Jesus Christ as Lord, with ourselves as your servants for Jesus’ sake. For God, who said,
“Let light shine out of darkness,” has shone in our hearts to give the light of the knowledge of
the glory of God in the face of Jesus Christ.
Paul is reflecting on the reality of Genesis 1:3 in this passage showing that the gospel (the voice of God in the Word of God) is still speaking into the darkness and chaos of sin. The power of the kingdom of light (Christ) is overcoming the kingdom of darkness (Satan) in man. The devil wants to blind eyes, not from hearing, but seeing (in the hearts) the light of the gospel.
The way God created all things (speaking light into darkness) is, not only, the way Christ, the Light of the world, defeated the domain of darkness (John 1:5; 8:12) but it is also the way we are sanctified, having the remaining effects of sin (darkness) overcome by the light of truth (Psalm 119:11; John 17:17; Ephesians 4:17-24).
The Bible is one large narrative about light beating darkness. Think about the realities of darkness in your life: the emotional, social, spiritual, relational struggles that life and sin bring. None of these things flee because we want them to. No affection is changed simply because we are grieved by its presence. No relationship can see the darkness eclipsed because it's gone on too long. No, none of these things flee by self-will, self-help, or self-care. Darkness flees only when light arrives.
Whatever evidence of darkness in your life, remember that Christ has overcome it (John 1:5), so can you and, one day, it will be eliminated (Revelation 22:5). This is the tri-fold dynamic of our hope!