Summary: As Christians, who have put on the new man in Christ, we are His light to world. We have no business walking in darkness rather we are expose what is in the darkness by shining the Light.
This series has been about putting on the new man, that we are a new creation in Christ, and what is should look like. Our theme for this series works around these two thoughts.
Ephesians 4:22a and 24a (NKJV) that you put off, … the old man ... and that you put on the new man …
Last week, we considered that we should be walking in the love of God as God is love and as children of God we need to imitate our Father, but the sins of the old man keeps getting in the way.Today, we are looking at being in the light. Jesus said:
John 8:12 (NKJV) Then Jesus spoke to them again, saying, “I am the light of the world. He who follows Me shall not walk in darkness, but have the light of life.”
As Christians, we are His light in the world and as such we become the light of the world.
Matthew 5:14–16 (NKJV) “You are the light of the world. A city that is set on a hill cannot be hidden. 15 Nor do they light a lamp and put it under a basket, but on a lampstand, and it gives light to all who are in the house. 16 Let your light so shine before men, that they may see your good works and glorify your Father in heaven.
Are we the light we are suppose to be? Are we shining His light for others to see their way to Jesus?
In 1973, a Cambodian schoolteacher and his wife came to know Christ in an evangelistic campaign. God called Sin Soum and his wife to move into a large refugee settlement outside Phnom Penh where there was not one Christian. It was a hard decision, for it meant personal hardships. Shopping meant a half-day’s journey, and the nearest water was a 15-minute walk. Their first shelter was a tiny thatch hut they built themselves.
In a short while that little hut was overflowing with people coming to study the Bible. In six months, 30 people had believed. In two years, this couple—untrained in evangelistic techniques—was shepherding a congregation of over 1,000 people, almost all of whom were their spiritual children or grandchildren. Such is the power of the Holy Spirit working through the nonprofessional. 
And we worry about being a light to our neighbor or coworker? Our call to be light and to walk in light is an active , not passive activity. Going to our focal verses, we need to put it into context. Look at the last two verses from last week.
Ephesians 5:6–7 (NKJV) 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 be partakers with them.
The world wants to lead you from the truth. The world wants you to desire and participate in the things they desire. They will use fancy words and flattery to move you to their side. Paul tells us to not partake in their sins. We are not to be what they are.
Ephesians 5:8 (NKJV) For you were once darkness, but now you are light in the Lord. Walk as children of light
Before our salvation, that is where we once were. We were not just in the dark, but Paul says we were darkness itself. And we were rescued from the realm of darkness.
1 Peter 2:9 (NKJV) But you are a chosen generation, a royal priesthood, a holy nation, His own special people, that you may proclaim the praises of Him who called you out of darkness into His marvelous light;
But now we are not just in the light, we have become the light. “but now you are light in the Lord.” We are light in the Lord. We are His children and we are to assume the nature of God and the very nature of God is Light.
1 John 1:5 (NKJV) This is the message which we have heard from Him and declare to you, that God is light and in Him is no darkness at all.
If God is light, and we are His children by the blood of Jesus, then we become light. And the command is: “Walk as children of light.” Are we walking in the light or in darkness, not our definitions of light and darkness, but how the Word of God defines it. There are those in the world who claim to be “enlightened,” but the Bible says they are in darkness, and they don’t know it. If we claim to know God and have fellowship with Him, yet our life is characterized by darkness, the Bible calls you a liar.
1 John 1:6 (NKJV) If we say that we have fellowship with Him, and walk in darkness, we lie and do not practice the truth.