Although the author never gives his name, up until the fourth century no one ever questioned that John the Apostle was the author. It was quoted by Polycarp in the early part of the second century, by Justin and Irenaeus in the middle part of the second century, and by Tertullian, Clement of Alexandria, and Origen in the later part of the second century. Apparently this epistle, together with second and third John, was written in the later part of the first century while John was in Ephesus. They may have been written to the churches in Asia Minor, over which John apparently took oversight.
The book is essentially a lesson on distinguishing true Christians from those who were not Christians. There are at least 14 tests. They can be used as a self-evaluation test. They also can be used to evaluate others.
