Epistolatory theology

Timothy Larsen (teaches at Wheaton College) posts on Epistolatory theology. He writes:

Is it just because I’m an evangelical, or is the letter an undervalued theological genre? No book of modern theology has had a greater impact on my thought than Bonhoeffer’s Letters and Papers from Prison. If only one work of Bonhoeffer’s could be saved for posterity, I would vote for it. If he had lived to send it to a publisher, however, I can easily imagine a catalogue of complaints and recommendations for re-thinking the project.

He notes that:

• The Epistles, after all, are our community’s favorite part of the Bible.
• There is something more explicitly relational and practical about letters
• He is reading the the four-volume Victorian life of the eminent Anglo-Catholic leader E. B. Pusey [I have never heard of him].
• Evangelicals have always had a special fondness for C. S. Lewis’s Screwtape Letters
• Larson also commends Luther's Letters of Spiritual Counsel.
• Another key letter is Martin Luther King’s Letter from a Birmingham Jail.

We could add to the list:

• Scot McKnight's Letters to Emerging Christians
• others?

I wonder if Larson has hit on something important here. In our age [whatever label you want to put on it] conversation and story are increasingly valued. And while letter writing is not common - we tend to use short emails or cryptic text messages, and short blog postings - I wonder if letter writing might/can become a theological/evangelistic/paedological tool, much like Brian McLaren's More Ready Than You Realize: Evangelism as Dance in the Postmodern Matrix.

What do you think?