Sorry, but that's poppycock. Of course we believe that the Grace of Jesus Christ is necessary for salvation.
But we don't pick and choose which scriptures we follow, as many sects of Christianity seem to do. We don't ignore the admonition of Christ, to keep His commandments.
We realize, though, that no matter how hard we try to do this, we're going to come up short, every time. And it is the grace of our Saviour Jesus Christ that makes up the deficit.
My own analogy is that of "tithing," which we Saints also observe to pay. Everything we have is the Lord's but He asks only that we pay 10% of our "increase" as tithing. We are NOT expected to give all we have, but He knows we can give SOMETHING, and thus His commandment that we pay 10%.
FWIW, the analogy is imperfect; I doubt that we can even keep 10% of the commandments, but the point is that we show a "good faith effort," trusting in the end that, after all we can do--which is the purpose of the Judgement, in fact--we are saved by the grace of our Lord and Savior Jesus Christ.
"And moreover, I say unto you, that there shall be no other name given nor any other way nor means whereby salvation can come unto the children of men, only in and through the name of Christ, the Lord Omnipotent." -- (Book of Mormon) Mosiah 3:17.