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Wacker and his wife visited with Graham at his home in Montreat four times over four years, beginning when Graham was in his late 80s.
The author remembers being surprised by Graham's humility and wit. When he first told Graham he was writing a book about him, Graham asked why.
"It just took me back," said Wacker. "And I thought a moment and then I said, 'Well, you've done some important things.' And he said, 'No.' He said, 'The Lord has done important things through me.'
When asked how Graham affected him personally, Wacker said, "He didn't fight. He did not respond to criticism, and some of it was vitriolic and some were death threats - death threats against his family- and he simply would not respond because he was so committed to the sense that he had something more important to do.
"And that's been I think, wisdom, for anybody to live with."