If there is one thing you could do to show a Mormon as to how how the Mormon faith is false, show them the issues behind the book of Abraham. If you don't know anything about the book of Abraham, it is part of their inspired Scriptures found in the Pearl of Great Price. Any attempt to defend this book as anything other than Egyptian paganism is completely and utterly futile. Watch this video. To understand how one could believe that Joseph Smith is a prophet after watching a video like this is beyond me.