Knowledge
If the goal is to determine the extent to which the concept of knowledge and related epistemological concepts are shared across cultures, then the focus on English in the West, and Sanskrit in the Classical Indian tradition, poses an obvious problem. For these literatures tell us nothing about the epistemic concepts of people in other cultures who speak, Chinese, Japanese, Korean, isiZulu, Quechua or one of the other approximately 6000 extant languages.
understanding
Our focus is on religious and cultural universality and differences in the commonsense concept of understanding. And while the philosophical and psychological literature mentioned in the previous paragraph provides many valuable insights into the folk concept of understanding that prevails in the West, the religious and cultural comparative project has yet to begin. To the best of our knowledge, there is no literature at all comparing the concept of understanding invoked by people in the West with the closest match to that concept that is invoked in Asian, South American, African or other cultures. Nor is there any empirical literature comparing conceptions of understanding among people of different religions.
wisdom
The psychological literature aimed at exploring the concepts of wisdom among people of different religions or cultures is rather sparse. Most of the studies that seek to determine how lay people define or conceive of wisdom have been conducted within a single culture, typically using either English-speaking North American participants or German speakers in Germany, and they have used a variety of methodologies making cross-cultural comparisons difficult. Information about the religious affiliations of participants is rarely collected or reported. The samples Takahashi and Bordia (2000) used to establish cultural differences were underpowered to detect reliable effects. Moreover, they focused exclusively on young undergraduate students studying psychology or liberal arts, raising the question of their representativeness.