Author and Date
Author
The author is John the apostle. In the first verses of both 2 John and 3
John the author identifies himself as "the elder." Note other similarities:
"love in the truth" (v. 1 of both letters), "walking in the truth" (v. 4 of
both letters) and the similar conclusions. See Introductions to 1 John and the
Gospel of John: Author.
Date
The letter was probably written about the same time as 1 and 2 John (a.d.
85-95). See Introduction to 1 John: Date.