Late in his life, about 90 AD, John wrote these three letters to help solve some problems in the home churches around Ephesus. These were churches John was overseeing as an elder, teacher and apostle. The problems involved weak leadership, heresy and false teaching; and John's solution was a return to the basic Christian doctrines of truth and love.
It is no coincidence that these letters follow those of James and Peter in our Bibles. Through these letters, John gives us a message that summarizes and reinforces James' call to live out our faith and Peter's call to holiness.
The Epistles of John share a common theme: living in the light of truth and love. This theme applies to Christians today every bit as much as it did when John wrote it over 2000 years ago.