Mormons define words differently than do Christians.
So when they say, for example, that "we believe that Jesus died on the Cross and rose from the dead" (if they do say that), they may be saying to each other something entirely different than what you would perceive them to be saying as a Christian.
Their understanding of biblical words is colored by mormon documents.
So you may be understanding them to be saying one thing, and within their ranks they believe something entirely different. If you were to actually become a mormon and were to be indoctrinated by them, you also would understand Christian terminology differently than most Christians, in the same way that mormons do.
If it were not the case, then mormonism wouldn't be another religion entirely. Nevertheless, it is.
There are things believed in mormonism that are so off-the-wall, that if mormonism were Christiianity, atheist would have no more conviction of sins; they would be laughing in our faces over the ridiculousness of our beliefs.
When atheists come across real Christian doctrine, however, they are convicted of their sins.
