How do you say mysticism in Japanese?
— 神秘主義

Generic synonyms for mysticism in Japanese
religion宗教 (しゅうきょう, shūkyō)
thought考え (kangae); 意見 (iken); 考慮 (kōryo); 思考 (shikō); 思索 (shisaku); 意図 (ito)