Here's Laughing With You!
In Chapter 11 of Screwtape Letters, Screwtape discusses humor, from joy to fun to jokes to flippancy. As to joy and fun, Screwtape thinks it generally promotes "wholly undesirable tendencies" including "charity, courage, contentment and many other evils." He especially likes flippancy which "deadens, instead of sharpening the intellect; and it excites no affection between those who practice it."

I offer this about Abraham Lincoln and his use of humor: "[Lincoln's humor] was much more than merely an attractive or entertaining feature of his style. Better than any American politician before or since, Lincoln understood humor as a form of communication that forges a partnership between speaker and hearer in which the former initiates the joke until the latter "get's it" and thereby closes the circle. He understood how a joke establishes intimacy through a feeling of confidential sharing that breaks down the heirarchy of the speaker/hearer relation." (From Andrew Delbanco, "Lincoln's Sacramental Language," p 209, in Our Lincoln, ed. by Eric Foner). In other words, humor can be a form of charity, a way to reach out to the Other in frienship. Let's try to "laugh with" someone today!