Carson, D.A., and Douglas Moo An Introduction to the New Testament - Second Edition. Grand Rapids: Zondervan, 2005. "New Testament Letters" Carson & Moo pp. 331-353
“1, 2, 3 John” Carson & Moo pp. 669-87
1 John, without a personal introduction stating who the recipient may be, and without a concluding section addressing immediate plans and bringing greetings, is not of the same nature as the letters of Paul. Carson and Moo suggest that the letter may have been intended to go to a number of congregations and have a more personal note to accompany it. They suggest that 2 John may be one such note, though 3 John does not seem to fit the “cover letter” pattern as well. There are references to the Johanine epistles by the end of the first century, though specific references to them as written by John do not appear until the middle of the second century. Scholars remain divided as to the authorship and dating of the letters. However, Carson and Moo tend to lean toward the epistles being written by the apostle John, as there is not adequate evidence to support a strong case for any other author. If the letters were written by John late in his life, the most likely source is Ephesus, where early tradition reports John settling. Dating of the letters is closely tied to the date of John’s Gospel. The epistles seem to have come after the gospel, as they make what seems to be passing reference to matters discussed in the gospel. Since 1 John also is alluded to in some subapostolic fathers, it seems to fit best in the early 90s, if not slightly earlier. The addressee of 1 John is not stated. 2 John appears to be addressed to a Christian congregation, not a particular person. 3 John is addressed to a Gaius, one of the most common names in the Roman Empire. Thus we have no clear identification of an addressee.
1 John speaks to certain errors in the Christian faith, errors which include denial of Christ’s bodily being. These errors are found in Gnosticism, though it is not fully-formed until the second century. They are found particularly in the Docetic beliefs, and can also be found, at least in part, in the heresy propounded by Cerinthus, someone known to John in Ephesus, where the two had a noted dispute.
The text of the letters is generally quite well documented, except for 1 John 5:7-8a which is not found in any early manuscripts but is found in some commentaries. 1 John was accepted in the canon quite early, though 2 and 3 John were accepted with more hesitancy. Recent scholarship has focused on identifying the community which may have written the letters in John’s name. Literary and rhetorical elements have also sparked interest among scholars. The theme which has contributed a great deal to Christian belief and practice is that innovation is dangerous. We are well advised to hold fast to that faith which was passed to us by the Lord through the apostles.