The word ecumenical has several different meanings. In the sense of “interfaith cooperation” for humanitarian relief, or to achieve other purposes for the common good, or for communal prayers, the LDS Church has always been willing to participate in or cooperate with other churches, including the Catholic Church. There is nothing new about that. We think that God hears the prayers of all people, not just of Mormons.
The most common way in which the word “ecumenical” is understood, however, is in relation to what is known as
“ecumenism,” or the “ecumenical movement,” which is a movement aimed at “uniting” all the churches together into one church—probably under the leadership of Rome. That is a movement which the LDS Church so far has not participated in, because of the unique theological position that it assigns to itself—as the Restoration of the original and true church of Christ. For example, the LDS Church has not joined the
World Council of Churches, which is one body having that kind of objective. (Interestingly, the Catholic Church has not joined the WCC either.) The only kind of “ecumenism” that we would recognize would be one in which they all agreed to be baptized Mormons!
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