D&C 22

Abinadi asks the priests of King Noah -

"...what teach ye this people?
28 And they said: We teach the law of Moses." (Book of Mormon Mosiah 12:27 - 28)

Then he asked -

"...Doth salvation come by the law of Moses? What say ye?" (Book of Mormon Mosiah 12:31)

They answered -

"...that salvation did come by the law of Moses." (Book of Mormon Mosiah 12:32)

This was also the understanding of the Jews at the time of Christ. Paul as well as other great teachers labored diligently to overcome this thinking. Paul wrote the Galatians -

"For I through the law am dead to the law, that I might live unto God." (New Testament Galatians 2:19)

Nephi more plainly taught -

"...notwithstanding we believe in Christ, we keep the law of Moses, and look forward with steadfastness unto Christ, until the law shall be fulfilled.
25 For, for this end was the law given; wherefore the law hath become dead unto us, and we are made alive in Christ because of our faith; yet we keep the law because of the commandments." (Book of Mormon 2 Nephi 25:24 - 25)

Therefore -

"...we talk of Christ, we rejoice in Christ, we preach of Christ, we prophesy of Christ, and we write according to our prophecies, that our children may know to what source they may look for a remission of their sins." (Book of Mormon 2 Nephi 25:26)

In modern day, early converts felt that some of their works before their conversion should be recognized specifically in regards to baptism. The Lord responded -

"BEHOLD, I say unto you that all old covenants have I caused to be done away in this thing; and this is a new and an everlasting covenant, even that which was from the beginning.
2 Wherefore, although a man should be baptized an hundred times it availeth him nothing, for you cannot enter in at the strait gate by the law of Moses, neither by your dead works." (Doctrine and Covenants Section 22:1 - 2)

It is through His restored priesthood, obedience to His commandments, and willing to enter into a new and everlasting covenant that His promised blessings come. The Lord explains -

"For it is because of your dead works that I have caused this last covenant and this church to be built up unto me, even as in days of old." (Doctrine and Covenants Section 22:3)

And then He commands -

"Wherefore, enter ye in at the gate, as I have commanded, and seek not to counsel your God." (Doctrine and Covenants Section 22:4)