When the emperor Constantine was converted to Christianity, he became aware of the divisiveness among the clergy concerning the nature of Deity. In an attempt to overcome this he gathered the eminent divines of the day to Nicaea in the year 325. Each participant was given opportunity to state his views. The argument only grew more heated. When a definition could not be reached, a compromise was made. It came to be known as the Nicene Creed, and its basic elements are recited by most of the Christian faithful.
You can find the full talk here: https://www.churchofjesuschrist.org/study/general-conference/2007/04/the-things-of-which-i-know?lang=eng