Tre, Mormons believe they are Christians but according to the bible they would not fit the biblical description of a Christian. One basic belief in Christianity is that the person believes Jesus Christ is God. I'm pretty sure Mormons do not believe this.
Can you ask your wife what is meant by "living the gospel?"
For them, it means reading 'the scriptures' and trying to be more like Christ in their daily lives.
They believe that God used to be a living, breathing man who lived on Earth, who died and was then promoted or 'exalted' to god-status. Apparently there are some hardcore regular Christians who believe the same or something similar, but for that to be true, wouldn't man have to have existed before God? Does not compute.
Mormons aren't really big fans of the regular bible. They use it, but only as much as necessary to make outsiders think that theirs is a bible-based religion. After all, if you're a church doing business in America, it means more money for you if you can point to biblical linkage in your teachings.
In their opinion, however, the Book of Mormon is more perfect than the Bible, because the Bible has been through too many translations, thereby damaging or distorting the word of God. They argue that Joseph Smith gave them the same BoM translation in 18-whatever that they read from today.