"My dear children, I write this to you so that you will not sin. But if anybody does sin, we have one who speaks to the Father in our defense - Jesus Christ, The Righteous One. He is the atoning sacrifice for our sins, and not only for ours but also for the sins of the whole world.” (vv.1-2)
Here the apostle John is admonishing the church not to sin. However, he also tells his readers that when they falter and give into their sinful nature, Jesus Christ, The Righteous One, stands in there (our) defense, and not just for them, but for the entire world.
Jesus himself in speaking on the subject of forgiveness said, “Every sin and blasphemy will be forgiven men, but the blasphemy against the Holy Spirit will not be forgiven” (Matthew 12:31). Meaning, one can not continue to deny the calling of the Holy Spirit speaking to one’s heart to come to come Jesus, and expect to find salvation. John speaking on the subject of knowing God wrote, “The man who declares to know God, but does not follow His commandments is hence forth a liar and truth does not live in him” (v.4).
Many people today claim to be Christians, but the love of God and the Word of God are not evident in their lives. Others, flat out deny Him. And because both have not accepted Jesus as LORD of their lives, they are not considered His children and His mercy does not apply. This is not because He is not willing that all should be saved, but because some men love darkness rather than light, while others want to remain of the world and not set themselves apart from it. In either case, not admitting their need for a savior.
John then goes on to say, to those who are obedient to His word, God's love is truly made complete in them (v.5), and they will walk as Jesus did (v.6), as children of the light, for His Spirit lives in them. Then, when they stumble, He will be there as an Advocate to the Father, interceding with His righteousness, and blotting out their sins.
All one needs to do to be a part of His family, His grace, His forgiveness, is to call upon the name of the Lord, confess you are a sinner in need of salvation, ask Him to rule and reign in your heart and life, and He will send His Spirit to live within you and guide you into all truth.
Hallelujah! What a savior.
The Truth: "Therefore, since we have a great high priest who has ascended into heaven, Jesus the Son of God, let us hold firmly to the faith we profess. For we do not have a high priest who is unable to empathize with our weaknesses, but we have one who has been tempted in every way, just as we are—yet he did not sin. Let us then approach God’s throne of grace with confidence, so that we may receive mercy and find grace to help us in our time of need.” (Hebrews 4:14-16)