Good question....
A Mormon may genuinely believe all that LDS Tradition says, even though the substantiation for the self-claims is completely lacking.
Now, he might say that he simply believes it to be true - in spite of no real evidence. He simply chooses to believe it is true. While I may not, I can affirm his honesty and accept his position as one of faith.
Ah, but when the Mormon shouts (as some do), but the Bible teaches that the LDS self-claims are true, then it's not unreasonable to ask "where?" Or when he says, "And history teaches that Jesus visited the Americas!" it's not unreasonable to ask "where?" When the Mormon says, "the LDS says it's true so that's proof!" or "The chosen Tradition of the LDS as the LDS itself so interprets and arbitrates so that's proof!" most of us would conclude that it's not. It's just self-authentication. And usually, in a moment of honesty, the Mormon will often admit that.
But which is worse? That is your question. To accept something as true while admitting one has no substantiation for it? Or insisting that one has substantiation for it but it's painfully obvious it's just circular, self-authenticating arguements based on the same self-claims?
I think the second is worse.
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