So Funny Piper Forgot to Laugh?

Below is a clip from a full sermon Pastor John Piper delivered to the American Association of Christian Counselors. You can watch the entire sermon here. I'm late getting to this, it was posted to Desiring God mid September. I couldn't believe the continuous response to Piper's words.

Lest anyone think I'm being ungracious to the counselors that laughed, consider that this was a conference they signed up for...I would assume they didn't blindly sign up, rather, they looked at what was going on and made an informed decision. After all, the AACC posted conference info just like any other organization does when it puts on a conference. Here's the link to it, and you'll note Piper is displayed prominently, along with a bio. Besides this, they had a schedule, and you may also observe that John Piper was part of the opening plenary session, not the stand-up comic opening throw a pie in your face and spray some seltzer down your pants session.