Many people who seek to prove the Church of Jesus Christ of Latter-day Saints wrong will sometimes claim that there have been changes to the LDS Temple ordinances. They use this as a weapon when referring to Joseph Smith's statement that "Ordinances instituted in the heavens before the foundation of the world, in the priesthood, for the salvation of men, are not to be altered or changed." (Teachings of the Prophet Joseph Smith, sel. Joseph Fielding Smith (1976), 308.)
In August, 1830, the prophet Joseph Smith received a revelation pertaining to the ordinance of the sacrament. In this revelation Joseph Smith was told "it mattereth not what ye shall eat or what ye shall drink when ye partake of the sacrament, if it so be that ye do it with an eye single to my glory—remembering unto the Father my body which was laid down for you, and my blood which was shed for the remission of your sins." (Doctrine and Covenants 27:2) In other words, food and drink, or bread and wine, were not the most essential elements of the ordinance.
Symbolism is a language like any other. Different symbols mean different things to different people in different cultures. The Temple endowment was revealed in English, but has since been translated into many different languages. Similarly, there have been minor changes in some of the symbolism of the Endowment over the years, however, the fundamental message, central covenants, and bestowal of authority have remained the same.
There have also been minor changes in the covenants made during the Endowment. For example, after the Death of Joseph Smith, Brigham Young added "The Law of Retribution" to the Endowment. When the Saints began to gather to the Salt Lake Valley, a covenant to help all people gather was also introduced by revelation. These covenants were given by revelation with regard to very specific historical situations and were later removed by revelation when the historical situation that caused them to be added changed. This illustrates the flexibility inherent in the ordinances. It is the central covenants and core message that can never change, while many peripheral symbols and covenants are subject to change when inspired by revelation to the Lord's prophet.
Recent changes to the Temple endowment within the last 20 years have involved the removal of the Penalties, the translation of certain parts of the ordinances back into English, minor changes in the dramatization, and minor changes in the manner of administration of the Initiatories. None of these changes have affected the central message, covenants, or authority presented in the temple.