The Law to the Church—Restatement of the Decalogue
18 And now, behold, I speak unto the church. Thou shalt not kill; and he that kills shall not have forgiveness in this world, nor in the world to come.
19 And again, I say, thou shalt not kill; but he that killeth shall die.
20 Thou shalt not steal; and he that stealeth and will not repent shall be cast out.
21 Thou shalt not lie; he that lieth and will not repent shall be cast out.
22 Thou shalt love thy wife with all thy heart, and shalt cleave unto her and none else.
23 And he that looketh upon a woman to lust after her shall deny the faith, and shall not have the Spirit; and if he repents not he shall be cast out.
24 Thou shalt not commit adultery; and he that committeth adultery, and repenteth not, shall be cast out.
25 But he that has committed adultery and repents with all his heart, and forsaketh it, and doeth it no more, thou shalt forgive;
26 But if he doeth it again, he shall not be forgiven, but shall be cast out.
27 Thou shalt not speak evil of thy neighbor, nor do him any harm.
28 Thou knowest my laws concerning these things are given in my scriptures; he that sinneth and repenteth not shall be cast out.
29 If thou lovest me thou shalt serve me and keep all my commandments.
President Joseph Fielding Smith wrote:
“Strange as it may seem, there are some people who believe that the Ten Commandments pertained to the law of Moses, and therefore when Christ came, these laws of the Decalogue were done away. Nothing could be farther from the truth. There is not a single commandment in the Decalogue that was not accepted by the people of God as a commandment from the very beginning. In this revelation [D&C 42] the Lord again declares these great governing laws are binding on the members of the Church. They are not all mentioned in detail, but those which are not so mentioned are included in the saying: ‘Thou knowest my laws concerning these things are given in my scriptures; he that sinneth and repenteth not shall be cast out’ [D&C 42:28]. That is, he who violates these laws and will not repent must not be retained in the Church. Previously we had been commanded to serve God and worship Him in spirit and in truth at the time of the organization of the Church [see D&C 20] and at that time many other commandments were given. Later the Lord declared that we should observe the Sabbath day to keep it holy, which will be discussed in a later revelation. So, we see, in this dispensation of the fulness of times, the Lord restated these fundamental laws and commanded us to observe them with the strictest obedience.”
(Church History and Modern Revelation, 2 vols. , 1:185.)