"These things have I written unto you that believe on the name of the Son of God; that ye may know that ye have eternal life, and that ye may believe on the name of the Son of God." The Epistle was written to people who already believe that Jesus is the Christ, but have never been sure of their present position or their possession of eternal life. "That ye might know." If you have any doubt as to the person, life, and atoning death of Jesus, as to His messiahship, or His divinity, read the Gospel. But if, after having believed the message of the Gospel, you are still perplexed about the assurance of your salvation, whether you really possess eternal life or not, read the Epistle. It was written to "you that believe on the name of the Son of God; that ye may know that ye have eternal life." The Epistle of John is the Epistle of fellowship. God wants His people to be in communion with Him, and John shows us the way to fellowship with God.