"We may talk of men being redeemed by the efficacy of his [Christ's] blood; but the truth is that that blood has no efficacy to wash away our sins. That must depend upon our own action." LDS Apostle Amasa M. Lyman, Journal of Discourses, Vol. 7, p. 299, 1859
Answer: Nope.
I’m a Mormon Christian, and I disagree with Lyman’s statement.
My statement concerned those who are members, but are somehow led, by the Holy Spirit, to Christ anyway. Is this a possibility? I don't know, and neither do you. I think it improbable, but impossible? I leave that to God, and in the meantime will treat them as any other person who is not a Christian.
The requirements for salvation are simple. While I believe in a true doctrine, and lots of false ones, even in the Christian Church, one doesn't have to believe it all down to the jot and tittle to be saved. One doesn't even have to know it all.
I'm a modified Calvinist, myself. I can't quite believe in predestination, but I believe God knows whether or not you will be saved in the end.
I believe baptism is commanded by Christ, but I don't believe it has any power to salvation in itself. I don't believe that the communion bread is the actual body of Christ, or that taking communion has value to save. I don't believe that a priest can forgive sins, although I do find value in confessing to another person. Does that make me a non-Christian? There are those that would say so.