Since the LDS reject the hallmark of the Trinity, some would not call them Christian.
The Nicene Creed was never preached by Christ. The Biblical passage which supposedly provides the best support for it, the Johannine Comma, was inserted by a monk into the Vulgate verions hundreds of years after Christ, as every serious Biblical scholar acknowledges.
Christ explained what “oneness” meant in his intercessory prayer in John 17:20-23:
“Neither pray I for these alone, but for them also which shall believe on me through their word;
That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou has sent me.
And the glory which thou gavest me I have given them; that they may be one, even as we are one;
I in them, and thou in me, that they may be made perfect in one; and that the world may know that thou hast sent me, and hast loved them, as thou has loved me.”