Christian love is a reflection of God's love for us. Persistence in loving proves that one is born of God and knows God. Mere claim to loving God accompanied by hating (or not showing love to) one's brother is a lie (chapter 2:9-11). The reason is because love is of God.
This follows the warning about false spirits, or teachers: these are not to be loved, nor should we pray for their well-being, for they are children of the Devil. It is good to pray for the lost sinner who will turn to Christ if we can just get the Word to him, and we shall show our love for him by introducing him to the Gospel of the Lord Jesus.
Believers are to love one another with the kind of love God loves us: it is not a physical attraction, nor a sentimental or social love, nor is it of the kind we have for friends whom we delight in being with. Only the Spirit of God makes it possible, and enables us to extend it to others. There are some believers who are very unlovable, from the human viewpoint, but in spite of that, God's love in us will prompt us to be concerned for their well-being.
When we meet a person who says he is a believer, and we find that he loves us and loves other brethren, we can know that he is a born-again child of God. On the other hand, a person who shows no love for us and other believers has never got acquainted with God, for God is love (this does not mean that love is God, as is preached by some heretics: God is also light [chapter 1:5], spirit [John 4:24] and eternal life [chapter 5:11]).
The love of God was manifested in us (not "among us" nor "to us"): because He has sent His only begotten Son, that we may live through Him; Jesus Christ is the life (John 14:6), and He lives in us (Galatians 2:20). This life begins when we receive Him as our Lord and Saviour.
When Jesus Christ is called "the only begotten Son," it refers to a unique relationship with the Father. A person is not a real father if he doesn't have progeny of his own seed, likewise we cannot have an eternal Father without an eternal Son sharing his divine essence. The Son was not created. God called the created angels His "sons", and He adopts those who trust Christ as "sons", but only the Lord Jesus is called by the Father "My only begotten Son," because only He is exactly like the Father in all His attributes, character and substance.
This is also the qualification used for Isaac in relation to Abraham, because he was unique and his birth was miraculous; by the time Isaac was born Abraham already had his son Ishmael (Hebrews 11:17), but Isaac stood in a special relationship which was not shared by Abraham's other sons: he was the "son of the promise", by whom would come the Seed in whom all the nations of the earth would be blessed.
There is a sharp contrast: not that we loved God, but that He loved us, and proved it in sending His son. Christ is called "the propitiation for our sins" which means that He is the "mercy seat" for our sins: He died for our offences, and was raised again for our justification (Romans 4:25). He has made expiation for our sins so that we can come with boldness to God's throne of grace, called a throne of grace because there is mercy there for us.
The Godly kind of love isn't found in nature, but at Calvary. The human kind of love is a response to love, but Godly love takes the initiative. The Lord Jesus proved His love by laying down His life for us, when we were yet sinners (Romans 5:8), in order to give us life by means of His death, and that is the proof of His love. It is this kind of love that is to be revealed in us, if we are His children.
Twice in this chapter John gives us the definition, "God is love" (verses 8 and 16), and we can also say "God is holy" because that is what "God is light" means. We will never find in the Bible the words "God is mercy", or "God is grace" or even "God is justice", and the love of God does not itself save us. Although He is love, He just cannot "let down the bars of heaven" and bring us in the front door, nor can He slip us in through a "back door" of heaven under cover of darkness.
God cannot do that because He is a holy and righteous God, and all sinners have to pay the penalty for sin, which is eternal death. His love cannot overlook that. That is why God gave His Son to die on the Cross for you and me, to pay the penalty for our sin. That opens the way for us, if we will accept it, so that holy God may reach down and save us for He can only do it on that basis (John 3:16, 14:6, Romans 5:8).
It is nonsense to think that because God is love, everything will work out all right and everyone will ultimately go to heaven. Those who prefer to ignore what God has done and not to believe in Christ, remain under the penalty for their sin, which is eternal death.
God has showed the nature of His love for us, and we ought to love our brothers and sisters in the same manner. It is not loving for a selfish motive, and it goes beyond returning the love others have for us. It is not a question of backslapping, calling somebody "brother," or behaving so nicely in the church, but it means having a concern for the well-being of other believers, as much as a concern to get out God's Word, and to serve Him. Are we able to forgive those who have hurt us and harmed us and yet profess to be children of God?
Although God manifested Himself in some form to various people in the Old Testament, He has never revealed Himself in all of His fullness. Those men saw the Son of God before He came to earth, translated "The LORD" in the English Bibles, in what is known as a theophany, often visible in the form of "the Angel of the Lord". God is a Spirit invisible to human eyes, and that is the way we worship Him. The Lord Jesus said to Philip, "He who has seen Me has seen the Father…" (John 14:9), but He was veiled in human flesh, so much so that multitudes who saw Him did not recognise Him.
God today can manifest Himself through believers loving each other. The world in general may not see the Lord Jesus as He is revealed in the Word of God, but they will know of God's love through the lives of believers. This is how the love of God is manifested in us. The world knows nothing about the love of God, but His love is developed in us, and the world has seen it in the lives of a great many believers.
The Christian's consciousness of the fact of God dwelling in him is due to the Spirit of God whom God has given. This gift of God is proof of our fellowship with God: it is not a human love, but fruit of the Spirit (Galatians 5:22-23). Joy and peace come out of love (1 Corinthians 13). If we are filled by the Spirit of God who indwells us, we are going to manifest this kind of love to the world.
John was qualified to bear witness of the Gospel, as the Lord Jesus had charged the disciples to do (Acts 1:8), and this is the message which we have to give. It is the purpose of our love, which reveals itself when we take Christ to a lost world of sinners. It is hard for them to understand why Christians bring them a message of love, and a lot of people to whom we witness are very hard to love.
The confession of the deity of Jesus Christ implies surrender and obedience also, not mere lip service (cf. 1 Corinthians 12:3; Romans 10:6-12). It is proof (if genuine) of the fellowship with God (chapter 1:3; 3:24). If we love God, love the Lord Jesus, and love one another as brothers and sisters in the faith, our love is made "perfect" (complete) and that will give us boldness, and we will not have any fear of the day of judgement. We are just like the Lord Jesus, and we are accepted in Him.
If we do not love our brother, then we do not love God either, for it is His commandment that we love one another as proof that we love Him.
8 Beloved, let us love one another; for love is of God, and he who loves is born of God and knows God.
8 He who does not love does not know God; for God is love.
9 In this the love of God was made manifest among us, that God sent his only Son into the world, so that we might live through him.
10 In this is love, not that we loved God but that he loved us and sent his Son to be the expiation for our sins.
11 Beloved, if God so loved us, we also ought to love one another.
12 No man has ever seen God; if we love one another, God abides in us and his love is perfected in us.
13 By this we know that we abide in him and he in us, because he has given us of his own Spirit.
14 And we have seen and testify that the Father has sent his Son as the Saviour of the world.
15 Whoever confesses that Jesus is the Son of God, God abides in him, and he in God.
16 So we know and believe the love God has for us. God is love, and he who abides in love abides in God, and God abides in him.
17 In this is love perfected with us, that we may have confidence for the day of judgement, because as he is so are we in this world.
18 There is no fear in love, but perfect love casts out fear. For fear has to do with punishment, and he who fears is not perfected in love.
19 We love, because he first loved us.
20 If any one 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.
21 And this commandment we have from him, that he who loves God should love his brother also.