Why are Mormon Temples Ceremonies kept secret from non-Mormons?

Even though only priests were allowed into the Temple in the Old Testament, all of the ceremonies and furnishings were described in great detail in the Old Testament for anyone, Jew or Gentile alike, to read and understand. However the details of Mormon Temple Ceremonies are kept secret, and, in fact, non-Mormons are prevented from even entering Mormon Temples. The LDS website says > You can talk about what the interior of the temple looks like, and you can freely share the feelings you have in the temple. However, temple covenants and ordinances, including the words used, are too sacred to be discussed in detail outside the temple. By avoiding discussion of these sacred things outside the temple, we protect them from mocking, ridicule, or disrespect. Do not be casual when talking about your experiences in the temple. ([lds.org](https://www.lds.org/liahona/2010/10/commonly-asked-questions?lang=eng)) What is the reason for keep the ceremonies secret? Why are they considered 'too sacred'?