Matthew 5

We learn a great deal about the "doctrine of Christ" and His gospel in the Book of Mormon (see 2 Nephi 31, 3 Nephi 11, 3 Nephi 27).  As the Lord gives His Sermon on the Mount, we see the same doctrine and pattern as He tells his disciples -

"And Jesus, seeing the multitudes, went up into a mountain; and when he was set down, his disciples came unto him;
2 And he opened his mouth, and taught them, saying,
3 Blessed are they who shall believe on me; and again, more blessed are they who shall believe on your words, when ye shall testify that ye have seen me and that I am.
4 Yea, blessed are they who shall believe on your words, and come down into the depth of humility, and be baptized in my name; for they shall be visited with fire and the Holy Ghost, and shall receive a remission of their sins  (JST Matthew 5:1-4)

First there is faith or belief on His words, humility or repentance, baptism in His name, and being visited by the Holy Ghost.  And then conditions or qualifications to live in the Celestial kingdom, which means, enduring in obedience to the end.  Such conditions include -

"Blessed are the poor in spirit: for theirs is the kingdom of heaven.
4 Blessed are they that mourn: for they shall be comforted.
5 Blessed are the meek: for they shall inherit the earth.
6 Blessed are they which do hunger and thirst after righteousness: for they shall be filled.
7 Blessed are the merciful: for they shall obtain mercy.
8 Blessed are the pure in heart: for they shall see God.
9 Blessed are the peacemakers: for they shall be called the children of God.
10 Blessed are they which are persecuted for righteousness' sake: for theirs is the kingdom of heaven.
11 Blessed are ye, when men shall revile you, and persecute you, and shall say all manner of evil against you falsely, for my sake."  (New Testament | Matthew 5:3 - 11)

In my mind, "poor in spirit" that come unto the Savior suggests faith in Jesus Christ.  "They that mourn" suggests to me sorrow for sin and sincere repentance.  In my mind, all of this follows the Doctrine of Christ.