Best known for the No. 1 hit "Nobody Knows," Sharp died Saturday of complications from past stomach surgeries and digestive issues, according to his Website.
A musician raised in Redding, Calif., Sharp followed an unconventional path to success.
Diagnosed as a young man with the blood cancer Ewing's sarcoma, he battled for his life while undergoing chemotherapy and radiation.
The Make-a-Wish Foundation, which grants requests to terminally ill children and teens, learned he was an aspiring musician and arranged a meeting with famed music producer David Foster, which led to a record deal.
His debut 1996 album Measure of a Man went gold on the strength of "Nobody Knows." Other albums followed and Sharp became a motivational speaker, heavily involved in Make-a-Wish.
"I feel like I'm here for a purpose," he told PEOPLE in 1996. "I've learned to love unconditionally, to appreciate life."
A memorial is being planned for Nashville.