Again, this is not a thread about Mormonism. But I must assume that to you truth is relative.
If Woody, Mom and lmp say: "Jesus rose from the dead."
We can be in agreement.
But if WhiteMountain, a Mormon says: "Jesus rose from the dead."
Then, by your train of thought, I must disagree with him or risk that I would be unequally yoked.
Eternal truths are eternal truths. They do not become untrue just because someone only grasps some of them and not all.
No, if WM proclaims that "Jesus rose from the dead" then he will be proclaiming the most incredible news the world has ever know. Too bad that he is not in a position to enjoy it. You should be telling him that he will have to look on the Lord Jesus from the Lake of Fire.