I didn't say you were mistaken, I said you (and I) were not qualified to be the judge. Only God is the judge.
But I’m not judging. Judgement requires opinion. It’s not my opinion that Mormons are not Christian. Mormons are Mormons because they follow Mormonism. Christians are Christians because they follow Christ/the Bible. These are two different things. Opinion or judgement play no role.
Mormonism and Christianity are not the same. The theology differs, the history differs, the beliefs differ. My favorite Lincoln quote sums it up...”How many legs does a dog have if you call the tail a leg? Answer, “4”. Calling a tail a leg does not make it one”.
Upon WHAT do you judge this assertion to be true?