Author: 1, 2, and 3 John have from earliest times been  attributed to the apostle John, who also wrote the Gospel of John. The content,  style, and vocabulary seem to warrant the conclusion that these three epistles  were addressed to the same readers as the Gospel of John.

Date of  Writing: The Book of 1 John was likely written between A.D.  85-95.

Purpose of Writing: The Book of 1 John seems to  be a summary that assumes the readers’ knowledge of the gospel as written by  John and offers certainty for their faith in Christ. The first epistle indicates  that the readers were confronted with the error of gnosticism, which became a  more serious problem in the second century. As a philosophy of religion it held  that matter is evil and spirit is good. The solution to the tension between  these two was knowledge, or gnosis, through which man rose from the mundane to  the spiritual. In the gospel message, this led to two false theories concerning  the person of Christ, Docetism—regarding the human Jesus as a ghost—and  Cerinthianism—making Jesus a dual personality, at times human and at times  divine. The key purpose of 1 John is to set boundaries on the content of faith  and to give believers assurance of their salvation.