Excerpt from an October 2018 General Conference address by Russell M.Nelson:

Thus, the name of the Church is not negotiable. When the Savior clearly states what the name of His Church should be and even precedes His declaration with, “Thus shall my church be called,” He is serious. And if we allow nicknames to be used or adopt or even sponsor those nicknames ourselves, He is offended.

What’s in a name or, in this case, a nickname? When it comes to nicknames of the Church, such as the “LDS Church,” the “Mormon Church,” or the “Church of the Latter-day Saints,” the most important thing in those names is the absence of the Savior’s name. To remove the Lord’s name from the Lord’s Church is a major victory for Satan. When we discard the Savior’s name, we are subtly disregarding all that Jesus Christ did for us—even His Atonement.