The book of 1st John is a General Epistle (Apostolic Letter). It is written by the Disciple/Apostle John around 85-95 A.D. probably from Ephesus. The key personalities are the Apostles Peter and Paul. Its purpose was to warn about the increasing threat of false teachings and to reassure Christians of their faith and love in Jesus Christ.
It was written to combat false teachings that had to do with the denial that Jesus had a genuine human body (1:1). This Gnostic view of matter as being evil led to two responses, asceticism or licentiousness. He very clearly writes to give the true tests of a true Christian. These tests also contradicted the Gnostic licentious approach to Christianity. He gives several means to measure the reality of one’s conversion experience.
• Chapters 1-2, John reassures believers explaining, “God is Light and in Him is no darkness at all” (1:5). He wrote that if sins were confessed He would cleanse them, because Jesus is the propitiation for “the whole world” (2:2). Because John was aware of the continuing attack of false teachings, he then urged believers not to love and follow after the world because it was not of the Father, and would ultimately pass away. Discernment is necessary to thwart the constant attacks of heresy.
• In chapters 3-4, He teaches about the love of God and that through His love He sent Jesus, “To destroy the works of the devil” (3:8). Therefore, believers should love each other not only with words but also, “in deed and truth” (3:18), as Jesus commanded.
• Chapter 5, John exhorts Christians to live by faith because through our faith in Christ we overcome the wickedness of the world. In addition, John writes one of the most powerful and assuring statements concerning the work of Jesus on the cross, “These things I have written to you who believe in the name of the Son of God, so that you may know that you have eternal life” (vs. 13). John wanted all believers to know 100%, that because of their faith and trust in Jesus Christ they would spend all of eternity with Him.