³ But sexual immorality and all impurity or covetousness must not even be named among you, as is proper among saints. ⁴ Let there be no filthiness nor foolish talk nor crude joking, which are out of place, but instead let there be thanksgiving. ⁵ For you may be sure of this, that everyone who is sexually immoral or impure, or who is covetous (that is, an idolater), has no inheritance in the kingdom of Christ and God. ⁶ Let no one deceive you with empty words, for because of these things the wrath of God comes upon the sons of disobedience. ⁷ Therefore do not become partners with them; ⁸ for at one time you were darkness, but now you are light in the Lord. Walk as children of light ⁹ (for the fruit of light is found in all that is good and right and true), ¹⁰ and try to discern what is pleasing to the Lord. ¹¹ Take no part in the unfruitful works of darkness, but instead expose them. ¹² For it is shameful even to speak of the things that they do in secret. ¹³ But when anything is exposed by the light, it becomes visible, ¹⁴ for anything that becomes visible is light. Therefore it says,

Darkness is the absence of light; it is what happens when light is removed or unavailable. The term “darkness” is used by many of the New Testament authors to describe the moral and spiritual state of mankind apart from God. Without God, humanity is left in a state of darkness. The apostle John described God as light-producing and darkness-dispelling.

This is the message we have heard from him and proclaim to you, that God is light, and in him is no darkness at all. – 1 John 1:5 ESV

God brings light into the world, illuminating and eliminating darkness wherever His presence dwells. So the spiritual darkness in which mankind finds itself is the result of an absence of God. Since God is omnipresent, there is no place where He does not exist, but when men fail to acknowledge His presence, power, and authority over their lives, they find themselves plunged into spiritual darkness.

David wrote, “Only fools say in their hearts, “There is no God.’ They are corrupt, and their actions are evil; not one of them does good!” (Psalm 14:1 NLT). Failure to believe in God does not make Him go away; it simply plunges the disbeliever into further darkness and despair. John described Jesus as the Word of God that “existed in the beginning with God” (John 1:2 NLT). He further noted that God created everything through him, and nothing was created except through him” (John 1:3 NLT). As the light of God, Jesus “gave life to everything that was created, and his life brought light to everyone. The light shines in the darkness, and the darkness can never extinguish it” (John 1:4 NLT).

Yet, while the spiritual darkness of the world cannot extinguish “the light of life,” it does not prevent humanity from preferring darkness to light.

God’s light came into the world, but people loved the darkness more than the light, for their actions were evil. All who do evil hate the light and refuse to go near it for fear their sins will be exposed.– John 3:19-20 NLT

Jesus describes Himself as the light of the world.

“I am the light of the world. Whoever follows me will not walk in darkness, but will have the light of life.” – John 8:12 NLT

In his first letter, John points out that a relationship with Jesus, the light of the world, precludes living in darkness. It is impossible to walk in the light and darkness at the same time. 

If we say we have fellowship with him while we walk in darkness, we lie and do not practice the truth. – 1 John 1:6 ESV

Our relationship with Christ should impact our conduct. That is why Paul tells us: “Take no part in the unfruitful works of darkness, but instead expose them” (Ephesians 5:11 ESV). As children of God, we have been exposed to Jesus Christ, the light of life. As John wrote in his gospel, “The Light shines in the darkness, and the darkness did not comprehend it” (John 1:5 NASB). Darkness and light cannot coexist. So when Jesus, the light, came into the world, He illuminated and exposed the darkness all around Him. He did not eliminate the darkness of sin because it was sinful men who orchestrated His death on the cross. However, everywhere Jesus went, His life shone like a beacon of hope in a sin-darkened world. He was God in human flesh, dispensing love, grace, mercy, and hope to a lost and dying world. Yet, the apostle John reveals that this life-giving light of God was met with ridicule and rejection by those dwelling in the darkness of sin. 

There was the true Light which, coming into the world, enlightens every man. He was in the world, and the world was made through Him, and the world did not know Him. He came to His own, and those who were His own did not receive Him.– John 1:9-11 ESV

But as many as received Him, to them He gave the right to become children of God, even to those who believe in His name, who were born, not of blood nor of the will of the flesh nor of the will of man, but of God. – John 1:12

There were many who preferred the darkness of sin over the Light, but some turned to the Light and gratefully received His offer of forgiveness and redemption. He exposed their sins and their need for a Savior. It is interesting to note that John says, “the true Light which, coming into the world, enlightens every man.” The Greek word John used is φωτίζω (phōtizō), and it can mean “to give light” or “to enlighten, spiritually, imbue with saving knowledge” (“G5461 – phōtizō – Strong’s Greek Lexicon (KJV).” Blue Letter Bible). Obviously, John was not indicating that every man was saved as a result of Jesus’ incarnation. But with Jesus’ death and resurrection, the message of salvation came into the world, exposing every man and woman to the truth; some received it, while others rejected it.

Paul’s letter to the Ephesians is addressed to those who have received the Light. He is calling them to live lives that reflect their new standing as “children of light” (Ephesians 5:8 ESV). He reminds them of the transformation that had taken place in their lives because of their faith in Jesus.

…for at one time you were darkness, but now you are light in the Lord. – Ephesians 5:8 ESV

Paul does not say, “you are in the light,” but “you are light.” They had been transformed. Not only had they been living in darkness, but they were darkness; their lives were characterized by the deeds of darkness. But the Light of the world had penetrated their lives, transforming them into children of light. Now, Paul was calling them to live as who they were.

This meant a change in behavior. Children of light were not meant to live like children of darkness. And Paul was very explicit in describing what life in the light looks like.

Let there be no sexual immorality, impurity, or greed among you. Such sins have no place among God’s people. – Ephesians 5:3 NLT

And just in case his audience got a bit prideful and puffed up, thinking they had no problem with those particular sins, Paul dropped a bombshell on them.

Obscene stories, foolish talk, and coarse jokes — these are not for you. – Ephesians 5:4 NLT

These are those “little” sins that so many Christians excuse as somehow acceptable to God. But Paul says, “These are not for you.” As Christians, it is so easy to rationalize our behavior. We can find it tempting to justify certain behavior as acceptable to God, but Paul lumps obscene stories, foolish talk, and coarse jokes in with immorality, impurity, greed, and idolatry. They are all deeds of darkness.

Don’t be fooled by those who try to excuse these sins, for the anger of God will fall on all who disobey him. – Ephesians 5:6 NLT

Those are not the characteristics of those who have become light; they mark the nature of those who are still children of darkness. That is why Paul goes on to adamantly demand a radical change in behavior.

Don’t participate in the things these people do. For once you were full of darkness, but now you have light from the Lord. So live as people of light! For this light within you produces only what is good and right and true. – Ephesians 5:7-9 NLT

As Christ followers, we are to determine what pleases God and do those things. We are to live differently from all those around us. The light within us is to produce what is good, right, and true. Rather than participate in the deeds of darkness, we are to expose them (Ephesians 5:11). This does not mean that we are to walk around pointing our fingers in judgment at those who sin, but that our very presence as light should provide a dramatic contrast. Paul says, “Their evil intentions will be exposed when the light shines on them, for the light makes everything visible” (Ephesians 5:13-14 NLT).

Our presence among those living in darkness and death will provide a convicting influence on their lives. When Christ followers live as lights in the darkness, their lives become beacons of hope, calling those living in the darkness of sin to experience the light of life. Our light-infused lives become a wake-up call to a lost and dying world.

Awake, O sleeper, rise up from the dead, and Christ will give you light. – Ephesians 5:14 NLT