John Continues to give assurance of our place in Christ, witnessed by the Holy Spirit and confirmed by a change in the way we live our lives. Love is the number one sign of our new life in Christ. Love for fellow believers, those around us in the world, and love for the Father. Our love for others shows in our actions towards them. We have a new concern and compassion for the needs of others and are willing to sacrifice our own comfort to give them the help that they need. Our love for God is shown primarily through obedience to his commands and love for his children.
John states repeatedly that our position in Christ is not earned, but comes by faith in Jesus as the son of God. In chapter 5 he takes on a heresy that would claim Christ only coming in spirit or in a non-corporeal form. John says the water of Christ's birth and the blood he shed at his death both testify to his coming in bodily form to live on this earth and die as the atonement for our sins. The Holy Spirit testifies to these truths in the lives of believers and we can trust his testimony, since it is God's testimony about his son.
Walking in confidence of God's love for us, trusting in his testimony about the life of his son, Jesus, allows us to live in obedient love for God and compassionate love for others.