John Crichton doesn't die in the comic. The storylines focus on his adventures and challenges without leading to his demise. It's one of the elements that keeps fans engaged and interested in his journey.
Pulp fiction novel John Travolta died because he was attacked by a mysterious dark magician in the second half of the novel and unfortunately died. The Dark Mage was an evil being who tried to devour John Travolta's soul in order to gain his power. But at the critical moment, John Travolta's friends and allies joined forces to help him get through this dangerous moment and finally save his soul.