The Letters of John present a puzzle. We know little about who they were written by or why, though they appear to be a response to a specific situation facing the church. Yet they seem the most timeless documents in the New Testament. This thorough study looks at the nature of the ethics of these letters, how this relates to John’s gospel, and what ethicists and commentators have made of it. It provides a brief but comprehensive survey of the key issues, and suggests how John is congruent with other NT and Jewish ethics.