The difference is one of eternal life. No one can come to the Father except through the Son. The Mormons know neither the Father nor the Son. They worship a false god. Would you not say that this is important?
It is not that I say that Mormons worship a false god, but it is the Scriptures that say it. If you hold to the basic law of logic, non-contradiction, something cannot be and not be at the same time. If the Mormons are right, then the entire Christian church is wrong. What Mormons believe and what the Christian church believes are contradictory.
In an age when the muslim population wants all Jews and Christians brutally murdered, I am more concerned with countering their actions, than deciding if another group meets your qualifications.
Very well said.