At the same time, it is a new commandment that I am writing to you, which is true in him and in you, because the darkness is passing away and the true light is already shining. – 1 John 2:8 ESV
John has made it clear that to claim to know God and to abide in Christ is little more than a lie if it is not accompanied by obedience and a lifestyle that emulates that of Jesus. Those who have truly come to know Christ and, as a result, have come to know the Father, should be experiencing the life-transforming power of His Spirit. John had heard Jesus make the promise, “I am the light of the world. If you follow me, you won’t have to walk in darkness, because you will have the light that leads to life” (John 8:12 ESV). And that was not the only time that John had heard those words from the lips of Jesus. “I have come into the world as light, so that whoever believes in me may not remain in darkness” (John 12:46 ESV). John was convinced that Jesus was the light of the world, and he was convinced that “the darkness is passing away and the true light is already shining” (1 John 2:8 ESV). He had witnessed the penetrating, life-changing power of the light in his own life and had seen it impact those around him. In just a short time, Christianity had spread throughout the known world. The apostles had taken their commission from Christ seriously and spread the good news regarding Jesus Christ to Jew and Gentile alike. Many had converted to Christianity. In doing so, they had come to know Christ as their Savior and sin-substitute. They had accepted His free offer of eternal life by acknowledging their sin and believing that His sacrificial death on the cross had paid the penalty for their guilt. His death had satisfied God and His resurrection had proved that He had been sent from God. The truth of that message had spread, penetrating the darkness of the world, and transforming the lives of those who had once lived in helplessness and hopelessness.
But that light was to continue to spread. It was to further permeate the lives of those who believed in Christ, exposing their sin in order that they might confess it. “If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness” (1 John 1:9 ESV). As the light expands in the life of the individual, it extends to those around him. The love of God, expressed through the life and death of His Son, is perfect or made complete in the lives of His children. God loved us by sending His Son. Christ loved us by giving His life. And when we love others as we have been loved, we complete the circle. Our love for others is an expression of our love for God. In essence, we are conduit through whom God loves those around us. And when we allow His love to flow through us to our brothers and sisters in Christ, we are expressing our love to Him. To refuse to love those whom God has chosen to love through the death of His Son is to question our love for God. Later on in his letter, John writes, “If anyone says, ‘I love God,’ and hates his brother, he is a liar; for he who does not love his brother whom he has seen cannot love God whom he has not seen” (1 John 4:20 ESV). We can't see God. We can't physically express our love to God. But when we love those who He has redeemed with the blood of His Son, we are loving Him. We become conduits of His love. Again, John tells us, “So we have come to know and to believe the love that God has for us. God is love, and whoever abides in love abides in God, and God abides in him” (1 John 4:16 ESV). The love of God resides in us. But that love is not to be hoarded. It is to be shared with those around us, especially those who share our faith and are part of the household of God. John gives us the motivation for our love: “We love because he first loved us” (1 John 4:19 ESV). Because we have experienced the gracious, merciful, undeserved love of God through the gift of His Son, we should love others, as an expression of our love for Him. So in essence, when we love others, we are loving God. That means the other person does not have to be loveable or lovely. They don't have to be deserving of our love. We are simply sharing the love of God and our love for God with them. “And this commandment we have from him: whoever loves God must also love his brother” (1 John 4:20 ESV).
When Jesus said, “Your love for one another will prove to the world that you are my disciples” (John 13:35 ESV), He was letting us know that the kind of love He was talking about was not of this world. He wasn't referring to human love, which is almost always marred by selfishness and a deep-rooted what's-in-it-for-me motivation. What Jesus had in mind was a supernatural, Spirit-empowered kind of love that starts with God and flows through His Son into the lives of those who place their faith in Him. That love, like light, is not to be hidden or hoarded, but shared with those around us. It is to penetrate and permeate the darkness. One of the greatest evidences of the reality of Christ's saving work is our capacity to love. It proves we are His disciples. And it reveals the love of God to those around us. “Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven” (Matthew 5:16 ESV).