When teaching recently on these three short letters, I considered them together in terms of their theme.
Three imperatives (taking the term loosely) for the letters appeared.
- 1 John — Test (4.1);
- 2 John — Do not receive (v. 10);
- 3 John — Support (v. 8).
If you know much about these letters, or have at least read them once or twice, you can put these together in a coherent whole.
The outline makes a compact summary of the letters, and a great lesson for preaching or teaching.