1

1-4: John and the apostles were eyewitnesses to the incarnate son of God. Jesus took on a physical human body to bridge the gap between sinful men and a holy God. John shared this message in hopes that others might also experience fellowship with God and with them. 

5-7: Sin cannot be in association with God any more than darkness can be in the presence of light. We cannot have salvation or fellowship with Him when we continue in the darkness of our own sinful, Godless path. But when we respond to the light (the truth of the gospel), the blood of Jesus cleanses us from all sin and we have eternal life. It is then that we are in God's will and walk in the light. John 1:4-5 equates light with life.

8-10:  Confession of sin is at the core of salvation. It's the first test John gives to see if we're in the faith. If we're ignorant of our sinful state, we won't see a need for Jesus' atoning work on the cross; the Gospel simply won't make sense. And if we don't receive Christ, we are dead in our sins. But if we confess our sins, God's word promises we'll be forgiven of all unrighteousness.

2

1-2: John is talking specifically to those whose "sins are forgiven" as indicated in verse 12. While obedience is a sign that we are saved, it doesn't mean our obedience is perfect. Christians still have a sinful nature and need Jesus as an "advocate with the father". This verse disposes of the notion that John is suggesting sinless perfection in order to be saved. Jesus not only died for John's audience but for everyone in the world who would put their trust in Him. 

3-6: Our habitual behavior is a visible gauge of our standing with God. If sin defines our life, it reveals that we are not regenerate. But if we live uprightly, it is evidence that we have truly been cleansed of our sins by the blood of Jesus. John is not saying that Christians never sin or that the heathen never do good deeds, he is simply saying that the way we live is a reflection of our spiritual state.

7-8: The command to love our brother (or neighbor) is not a new commandment since the Old Testament also commands us to love our neighbor. The newness of the commandment comes through Jesus showing us what this love looks like by example. He is the "true light that is already shining" mentioned in verse 8.

9-11: If we can sincerely hate others, it's a sign that we don't have a true understanding of the Gospel and are probably not saved. Once we understand that we too are wicked sinners capable of much evil, it's harder to become self righteous and think we are above their behavior. 

12-14: This section illustrates spiritual progression through the metaphor of physical growth. "Children" in this illustration are new believers who simply had their sins forgiven but lack in discernment and theological knowledge."Young men" are those who have  a strong knowledge of scripture and have experienced a level of victory over sin. "Fathers" are those who have a deeper knowledge of God.

15-17: John is speaking of the world system as indicated in verse 16. It's the love of lustful imagery, material wealth, and self exultation; it is not speaking about the planet.  If we love these sinful, perishable things more than God it indicates that we are not saved. These verses should cause the reader to realize the fleeting nature of sinful passions. 

18-19: According to these verses the term antichrist doesn't exclusively refer to an eschatological figure but to anyone in opposition with Jesus. Those who leave the faith were never truly born again to begin with and are by definition antichrists.

20-21: John makes it clear that his letter is for believers who have already been saved by Gods grace. The verses about obedience are not a way for unbelievers to attain salvation, rather, they're for believers to test wether or not they are truly regenerate. 

22-23: Jesus is the only way to God the Father. If we deny Jesus by attempting to reach God through works or by other means, we have denied the Father because His word says that faith in Jesus is the only way we can be purified of our sins.

24-25: Those who allow the Gospel message to abide in them until the end demonstrate that they have truly been saved by grace and have received eternal life. The passage of time often exposes false converts. 

3

1: It is loving for God to call us His children because we don't deserve it. Since all we have earned for ourselves is judgement, it was loving for Jesus to take our punishment on the cross, relieving us of the debt we couldn't pay in order to call us His children. Unsaved people do not understand our devotion to Christ because they do not understand what He did for us.

2: When we see Jesus face to face, a transformation will take place that make us like him both physically and spiritually. We don't know the details of this transformation, we just know that it's through Jesus.

3: Everyone who puts their hope in Christ for salvation (through repentance and faith) have His purity. We are then positionally perfect before God though we are sinners. This was only possible through the life, death, and resurrection of Jesus.

4-7: The way we live our lives reveals our spiritual state. Those who live a habitual, unrepentant, sinful lifestyle do not know Christ despite what they say. Their lives are in opposition to Jesus. Those who are of Christ strive for righteousness. John is refuting the Gnostics of his day who taught that since the physical body is evil and separate from the soul, it doesn't matter if we live in sin.

8-9: Someone who 'practices' sin is unrepentant and in need of salvation. This isn't talking about a Christian who struggles with sin, but a person who loves their sin and seeks ways to fulfill it. There is no outward evidence that they are battling against it. They have decidedly chosen the broad road of sin over the grace of God.

10: John gives us a general way to identify who the children of God are. If someone claims to have a relationship with God, their actions will show their desire for righteousness and love towards others.

11: God's message in the Old Testament that we should love one another still stands in the new covenant.

12-15: By murdering Abel, Cain revealed his spiritual condition. Love for others is a defining feature of someone who has been saved. It is much harder to hate others when we understand the Gospel. It puts things in their proper perspective so we don't look down on others in self righteousness. 

16: Jesus' willingness to lay down his life for us confirms God's great love for us. As his followers, we too should be willing to lay down our lives for others in love. 

17-18: Those of us who have been blessed with material wealth will give to others if God's love abides in us. When our love is manifest in deeds rather than words, it gives us a level of assurance that we are in Christ.

19-21: If our conscience condemns us, it's possible that we are trying to bear our own sin. But if we rely on His grace through Jesus, our heart does not condemn us and we can have confidence before God.

22-24: When we follow God's commandment to 'believe in the name of his son Jesus Christ and love one another' we are in close fellowship with him and conform to His will. And since our will is in alignment with His, we will receive what we ask for.

4

1: It seems that "testing the spirits" means to test a teacher's theology or message, which could have it's origin in evil spirits (rebellious angels). Since there are so many false prophets, we must have discernment and examine all truth claims in light of scripture. 

2-3: You can quickly discern if someone's message is from God by what they say about Jesus. If they deny the biblical account of Jesus being fully God and fully man ( Colossians 2:9) , their message is not from God because it is contrary to His word. 

4-6: Many people who claim to be Christians reject central biblical doctrines about Jesus. By doing this, they demonstrate that they are of the world (non-Christians).

7-8: Since love is one of God's attributes, we will mimic Him by loving one another if we are truly one of His children.

9-12: God's love was made manifest through His death on the cross as propitiation for our sins. If we love one another, it is evidence that we are saved and Christ abides in us.

13-14: The Holy spirit gives us assurance of salvation as well as our understanding that the Father sent the Son to pay for the sins of the world.

15-16: Through Jesus we can have an indescribably close relationship with God, in which The Holy Spirit actually dwells in us.

17-18: Since God's love is perfected in us through His plan of salvation, Christians no longer have to fear judgement. 

19: We did not merit God's love nor can we because he first loved us.

20-21: If someone has the capacity to sincerely hate another person, their claims to loving God are exposed as false. No one with a proper understanding of the Gospel can have a deep, permanent hatred for someone.

5

1: Faith in Christ is what makes someone a child of God.

 2-3: We show our love for God and our neighbors by obeying His commandments, which are not burdensome for the believer, but protect us as well as others. 

4-5: The only way to overcome the lustful world system of passing desires is through faith in Christ. In verse 5 John asks a rhetorical question to expound on eternal life through Jesus.

6-9: God's testimony that we receive eternal life through Jesus was demonstrated in three ways: the water, the blood, and the Spirit. Water most likely refers to the baptism of Jesus when God audibly confirmed that Jesus is the son of God. The blood refers to Jesus' death on the cross, fulfilling prophecy and giving confirmation of Jesus' deity through dramatic events such as they sky darkening and the temple curtain being torn in two. And the Spirit refers to the Holy Spirit who came down in the form of a dove during Jesus' baptism and was later poured out during Pentecost. These three dramatic events are God's testimony that Jesus is the Son of God.

10-12: If we put our faith in Jesus we receive the Testimony in ourselves, meaning, we receive the Holy Spirit. If we reject God's testimony that He gave us eternal life through Christ, we are essentially calling Him a liar. John then makes the very black and white statement that the source of eternal life is in God's Son, Jesus Christ. Nothing else can purify us from Sin.

13: The primary purpose of John's epistle is to give believers assurance of salvation.

14-15: God hears and answers prayers that are in accordance with his will. We can only know his will through the Bible.

16-17: I think the difference between sin that leads to death and sin that does not lead to death is a matter of true repentance. If we repent and put our trust in Jesus, sin no longer leads to death because Jesus paid for them on the cross. But if someone hasn't received God's grace, the sins they commit lead to spiritual death. A good example of this is the rich young ruler who chose the love of material wealth over Jesus. He trusted in his works and chose his sin instead of Jesus. Had he repented of this sin and received Christ, it would not lead to death even if he were to stumble into it again. His attitude toward this sin would then be hatred rather than love, and he would continue to be sanctified through the Holy Spirit.

18. Those who are born again no longer live an unrepentant lifestyle of sin that leads to spiritual death. Through Jesus' work on the cross, we are protected from Satan's power over us. 

19: Since Jesus is the only way to God, all who chose to rely on their good works, another god, or a spiritual experience are under Satan's power. 

20-21: John concludes his epistle by again proclaiming that Jesus is the only way to God and eternal life. All other roads lead to destruction, therefore we should keep ourselves from idols.