The context says:
When a knowing confronts a belief in a disease process, the knowing will always triumph. Kahunas were raised to abandon all doubt and to know.
Kahuna here is a hawaiian title for expert/teacher/healer, etc. From the above sentence, it seems to me that kahuna should know (disease) not just believe (what other people tells), right? but then why kahuna were raised to "abandon all doubt"? it should say "abandon all believes" instead? Pls suggest.
By the way, the overall context, the writer just want to highlight that you should know by yourself, from your experience, not just believe what other people say.
It seems to be saying the to heal yourself/others, you must maintain a positive attitude and resist uncertainty in your own understanding.