1-3 John

The most evident threat in all 1-3 John is Docetism.

See especially 1 John 4:2 and 2 John 7: The Apostle John warns that they are antichrists.

1 John

2 John

John wrote this letter to a local congregation, warning against the same false teaching as in 1 John: Docetism.

John warns of the danger of being hospitable to those false teachers (docetists).

John teaches that true fellowship is only possible under sound doctrine.

3 John

John warns of the double danger of the church: (1) false teaching (docetism) and (2) division.

So what we need is (1) discernment and (2) love.

Gaius

Diotrephes – loves to be first

Demetrius – well spoken of by everyone