Yes, it's true. One of the great Biblical scholars of our day taught a small Sunday School class and then preached to less than 100 people at Lakeside Community Church.
Dr. Kostenberger capably answered several tough questions about the book of John, from my "definition-of-world" multi-question to the reason why John 7:53-8:11 is included in the Bible. His working definition of "world" was surprisingly close to mine, but he added "in need of redemption," which I thought was helpful. He also noted that there could be some aspect of "Gentiles & Jews" (i.e., "the whole world" as opposed to Jews only) in John 3:16. I'm not opposed to "Gentiles & Jews" because, well, that pretty much encompasses every individual. You're either one or the other, right? In addition, he mentioned some passages where "world" clearly means "earth" or created universe, and showed how John can quickly switch between the two meanings.
As for the apparently spurious passage in John 8, Dr. Kostenberger said he has contacted Bible publishers and asked them to consider removing it. Although it's probably historically true, the passage lacks the needed textual evidence to be considered an authoritative part of the New Testament. Contrary to the impression given by Bart Ehrman, this is one of only two passages in the New Testament which fall into this category (the other is the famous "second ending" of Mark). An interesting point made during the Q and A session was that John's Gospel has many parallels with the book of Isaiah.
The sermon covered John 20:26-29, which is the account of Thomas' refusal to believe in the resurrection without physical proof. This was timely for me, as I had just confessed to my accountability partners that "my number one problem at the moment is unbelief." God is always the master of perfect timing, is He not? In the middle of the sermon, my 8-year-old daughter looked up at me and said, "Daddy, this is interesting - I like it!" Wow.
What struck me most about Dr. Kostenberger was the way he exuded humility. He was thoughtful, gracious and not quick to speak. It is rare to see such great knowledge and insight unaccompanied by the arrogance that sometimes results from learning. God's Word, rightly handled, does produce a remarkable humility and Christ-centeredness which are inspiring.
My pastor exhibits the same characteristics, and he's no theological lightweight himself. I'm grateful to God for providing these men as examples of character qualities I hope to attain, by grace, in His time.
I haven't figured out how to upload the audio files yet, but if I figure it out I'll offer them for the benefit of all interested THEOparadoxians.