Alma 11

The conversation between Zeezrom and Amulek provides some of the purest doctrine of the atonement, where in an attempt to destroy Amulek, Zeezrom asks (speaking of the Son of God) -

"...Shall he save his people in their sins?..." (Book of Mormon | Alma 11:34)

I believe that there are many that are Christians would answer - yes! But Amulek answered -

"I say unto you he shall not, for it is impossible for him to deny his word." (Book of Mormon | Alma 11:34)

Amulek would further explain -

"...I say unto you again that he cannot save them in their sins; for I cannot deny his word, and he hath said that no unclean thing can inherit the kingdom of heaven; therefore, how can ye be saved, except ye inherit the kingdom of heaven? Therefore, ye cannot be saved in your sins." (Book of Mormon | Alma 11:37)

Helaman would later reference this conversation as he taught his sons -

"...remember also the words which Amulek spake unto Zeezrom, in the city of Ammonihah; for he said unto him that the Lord surely should come to redeem his people, but that he should not come to redeem them in their sins, but to redeem them from their sins.
11 And he hath power given unto him from the Father to redeem them from their sins because of repentance..." (Book of Mormon | Helaman 5:10 - 11)

For -

"...he shall come into the world to redeem his people; and he shall take upon him the transgressions of those who believe on his name; and these are they that shall have eternal life, and salvation cometh to none else.
41 Therefore the wicked remain as though there had been no redemption made, except it be the loosing of the bands of death; for behold, the day cometh that all shall rise from the dead and stand before God, and be judged according to their works." (Book of Mormon | Alma 11:40 - 41)

Refering to Alma's question - on what conditions are we saved"

"...Faith in the Lord Jesus Christ; second, Repentance; third, Baptism by immersion for the remission of sins; fourth, Laying on of hands for the gift of the Holy Ghost." (Pearl of Great Price | Articles of Faith 1:4)

And endure to the end for -

"...if they will not repent and believe in his name, and be baptized in his name, and endure to the end, they must be damned; for the Lord God, the Holy One of Israel, has spoken it." (Book of Mormon | 2 Nephi 9:24)