All sacred ceremonies for the Mormon are performed in the temples. These buildings are for the very elect in Mormonism. If you haven’t tithed your 10% to the church and sat through the bishop’s interview to receive your temple recommend, you cannot take out your endowments inside the temple. For the Mormon this is absolutely necessary in order to receive a full salvation.
Teachings of the Prophet Joseph Smith, pg. 362; “…we calculate to give the Elders of Israel their washings and anointings, and attend to those last and more impressive ordinances, without which we cannot obtain celestial thrones.”