HBO released two statements about the upcoming episode which will re-enact parts of the LDS temple endowment, as reported here.
From creators Mark Olsen and Will Scheffer:
"In approaching the dramatization of the endowment ceremony, we knew we had a responsibility to be completely accurate and to show the ceremony in the proper context and with respect. We therefore took great pains to depict the ceremony with the dignity and reverence it is due. This approach is entirely evident in the scene portrayed in this episode and certainly reflected in Jeanne Tripplehorn's beautiful and moving performance as she faces losing the Church she loved so much. In order to assure the accuracy of the ceremony, it was thoroughly vetted by an adviser who is familiar with temple practices and rituals. This consultant was actually on the set throughout the filming of the scenes to make sure every detail was correct."
"We know that the writers/executive producers of the series have gone to great lengths to be respectful and accurate in portraying the endowment ceremony. That ceremony is an important part of this year's storyline. Obviously, it was not our intention to do anything disrespectful to the church. To those who may be offended, we offer our sincere apology. It should also be noted that throughout the series' three-year run, the writer/executive producers have made abundantly clear the distinction between the LDS church and those extreme fringe groups who practice polygamy."