Oct 10- Doctrine & Covenants 115:3

With everything that the saints were going through and struggling with, the Lord took the time to teach them that the proper name of the church was The Church of Jesus Christ of Latter-Day Saints. In our day, the Lord has chastened us and reminded us that we need to use the full name of His church as well. Both in 1838 and today there were probably those who wondered why, with everything else that is happening in the world today, why the Lord emphasized this? Perhaps this, both then and now, is trying to remind us whose church it is and that we are in His hands. 

Pres. Nelson

https://www.churchofjesuschrist.org/study/general-conference/2018/10/the-correct-name-of-the-church?lang=eng