Thanks for your questions. This is only a short answer space but I can make a general comment.
Tripitaka is taking the journey from China in the east to India where Buddha has his holy scriptures so the religion of Buddha can spread and people can come to the light. Throughout the story, the reader sees people worshiping in many ways, but they all have faith in their particular beliefs.
At one point in the story Buddha tells Tripitaka about how important and sacred the scriptures are and tells him that many religions come from this one religion. While reading the story the reader will see that the narrator takes you to different villages and cities and in each one there is a different god, deity or Immortal that is in control in that place. There are times when it is found to be a false idol, or god but each group has their own and worships faithfully whatever they choose as their belief.
Tripitaka and the others on the journey to the Buddha must have faith to believe they are doing the right thing. They must hold to the faith many times when they encounter difficult situations where it would be easy to give up their quest and return home.