2 John & 3 John
John's second letter is a mere 13 verses. Don't let that fool you. It offer seven points of spiritual wisdom every Christian should understand. His third letter is only 15 verses, but unites two essential themes: the importance of supporting what is good while correctly what is wrong in the church. Each study is a single lesson of teaching, so why not download and listen to each? You won't find a more compact study of spiritual truth anywhere.