First John is a pastoral letter written by the Apostle John to encourage believers to walk in true fellowship with God. He emphasizes three key themes: true doctrine, obedient living, and love for fellow believers. John warns against false teachers who deny Christ’s deity and exhorts believers to remain in the truth. He assures them of their salvation, teaching that those who abide in Christ will display righteousness, love, and obedience. The letter highlights the contrast between light and darkness, truth and falsehood, love and hate. Ultimately, John provides believers with confidence in their relationship with God, assuring them of eternal life through faith in Jesus Christ.