On January 11, 2006, Piper was told that he had prostate cancer. According to a letter sent to his church, he and his doctors thought that the cancer was not a big problem. When Piper talked about this he said, "This news has, of course, been good for me. The most dangerous thing in the world is the sin of self-reliance and the stupor of worldliness. The news of cancer has a wonderfully blasting effect on both. I thank God for that. The times with Christ in these days have been unusually sweet." Piper had surgery on February 14, 2006. He married Noël Henry in 1968, and they now have four sons, a daughter, and several grandchildren.