The end of exoteric knowledge is salvation. Since this is always something that occurs on the individual level and pertains to a specific person, we can describe it as a point of view is the “personal” or “interested,” as opposed to disinterested and impersonal.
For this reason, exoteric knowledge is by definition exclusive in both its means and its aim. In its aim, because it desires salvation and not knowledge or union or some other end; in its means, because it only concerns itself with what is required to achieve the salvation of an individual.
For example, the idea, in Catholicism, that “the Church” is one, regardless of where the faithful may be and even if they do not necessarily know that they are members in it, at the same time does not acknowledge the full validity of other religions. Even though this validity is included in the principle of the unicity of the Church, it cannot be integrated into Catholic exoterism because it has no value for the salvation of individuals, and in fact could present a serious danger for those who cannot comprehend it at the right level. For these persons it would result in a kind of religious indifferentism, or the idea that “all religions are the same.”
Esoterism is to exoterism as the spirit is to the letter.