Bestselling author Bear Grylls has survived a free-fall parachute accident that left him with a broken back, possibly unable to walk again; falling down a mountain in the Rockies, severing a finger in the Vietnam jungle, a broken shoulder in Antarctica. He passed the gruelling training to join the SAS, crossed the North Atlantic in an open inflatable boat, and held the highest ever open-air formal dinner party, in a balloon at 25,000 feet. But the hardest thing he has ever had to face, he says, is the death of his fatherIt was then, age 25, that he found what he describes in an interview with the Telegraph as ''a really lovely quiet faith that has been a powerful thing in our lives''. As he wrote in GQ magazine, ''Faith doesn''t mean you have to be especially "religious"But, in a nutshell, my faith tells me that I am known, that I am secure and that I am loved - regardless of the storms I may find myself in from time to time, regardless of how often I fall and fail.'' For the first