Ugh, if you’ve ever tried to tell a Mormon they don’t believe in the Bible, you know how frustrating it can be. The main problem, of course, is that they think they believe it! Getting past this can be a real challenge. You tell them they don’t believe it, they say they do, you tell them they don’t, they point out that they spend two out of every four years studying the Bible as part of their official curriculum, you say that doesn’t matter because they don’t teach the truth about the Bible, they point out everybody has their own interpretation of the Bible, you tell them that isn’t true, they say it is, and so on.
This ends up being yet another fruitless quest, because it’s so darned difficult to convince someone they don’t believe in something that they think they believe in. Mormons use the King James Version of the Bible, which is accepted by most Christians as being legitimate, so it’s not as though anti-Mormons can say they’re using a different version of the Bible than is commonly accepted.
One can point out that they don’t interpret scriptures the same way the rest of Christianity does, but this also poses problems, because there’s no way to prove what the correct interpretation is. You can amass evidence and build a case, but in most cases there’s no bulletproof proof, and of course Mormons aren’t going to accept what most Christian believe, because they claim to have modern-day prophets and other scriptures that tell them how to correctly interpret the Bible and they could care less what Christian scholars have said for the past 1,500 years. Actually, it’s not that Mormons care less, but they don’t give what has been commonly accepted much weight just because it’s been around for a long time.
So if you want to spend time trying to convince Mormons they don’t believe in the Bible you’re more than welcome to, but trust me, you’re just going to get frustrated in the end.