“There is a law, irrevocably decreed in Heaven before the foundations of this world, upon which all blessings are predicated—And when we obtain any blessing from God, it is by obedience to that law upon which it is predicated” (D&C 130:20–21).
http://www.lds.org/general-conference/print/2013/04/obedience-to-law-is-liberty?lang=eng
Surely there could not be any Doctrine more strongly expressed in the Scriptures than the Lord’s unchanging commandments and their connection to our happiness and well-being as individuals, as families, and as a society. There are moral absolutes. Disobedience to the Lord’s commandments will always deprive us of His blessings. These things do not change. God reveals to His Prophets that there are moral absolutes. Sin will always be sin. Disobedience to the Lord’s commandments will always deprive us of His blessings. The world changes constantly and dramatically, but God, His commandments, and promised blessings do not change. They are immutable and unchanging. Men and women receive their agency as a gift from God, but their liberty and, in turn, their eternal happiness come from obedience to His laws. As Alma counseled his errant son Corianton, “Wickedness never was happiness” (Alma 41:10).
In this day of the Restoration of the fulness of the Gospel, the Lord has again revealed to us the blessings promised us for being obedient to His commandments. May we ever be a light on the hill, an example in keeping the commandments, which have never changed and will never change.