The only chapter in the book as well. Another private epistle: to Gaius.
v. 2: 2 Beloved, I pray that all may go well with you and that you may be in good health, as it goes well with your soul.
This shows that one should pray for others' well being and health, in addition to their souls. But of course, this is still different from the Pentecostal way of "God is the Healer, you will be healed...I can see that God will visit you and heal you soon!"
v. 7: Gaius is known to welcome servants of God (possibly preachers).
v.8: Therefore we ought to support people like these, that we may be fellow workers for the truth.
v.9: Diotrephes, does not acknowledge John's authority, having his own autonomous mind, making vain accusations, not welcoming, etc. Not welcoming the brothers, hmmm, reminds me of some church that is too proud to welcome anyone.
v.10: John does not hide the ugly side of people, unlike many leaders in churches today.
v.14: "Friends" is used here again.
2 John & 3 John were private letters which John only provided summarized key points. To elaborate more, he would have to meet them as stated in the last part of the books, so that they could be edified.