As Lisa’s shaky legs stepped onto the zip line platform forty feet above the ground, she froze. “I can’t do this,” she whimpered. I reminded her how courageous she had been when she climbed to the top of our tower just a few minutes earlier. Now it was time for the reward—a 300-foot zip line ride to the ground. Lisa peered over the edge and swallowed hard. Her friends cheering from below looked so small from here. She looked up at me again. “Seriously, I can’t do this. I’m to