WRITER, The Apostle John. 
TO WHOM ADDRESSED, To the "Elect lady and her children." Some think this refers to a Christian matron and her family living in Ephesus, others that a church and its members are personified. If the first supposition is correct, this is the only book in the New Testament addressed to a woman.
EMPHATIC WORDS. "Love," which occurs four times, and "Truth, five times.
PURPOSE. The epistle was apparently written to warn friends against heresy and association with false teachers
2Jo 1:7-11
SYNOPSIS.
Main theme, a discourse on truth and error.
I. Divine Truth in its relation to believers.
(a) Unites them in fellowship
2Jo 1:1
(b) Eternally dwells in them
2Jo 1:2
(c) In connection with love, characterizes the spirit of their greetings
2Jo 1:3
(d) Loving obedience to, the pathway in which they walk
2Jo 1:4-6
II. Worldly Error.
(a) Has many deceitful advocates
2Jo 1:7
(b) Denies the incarnation of Christ
2Jo 1:7
(c) Must be guarded against
2Jo 1:8
(d) Departs from the teachings of Christ
2Jo 1:9
(e) The peril of fellowship with its followers
2Jo 1:10,11
III. Concluding words
2Jo 1:12,13
(Outline from Thompson’s Chain Reference Bible)