D&C 130: 20 There is a law, irrevocably decreed in heaven before the foundations of this world, upon which all blessings are predicated—
21 And when we obtain any blessing from God, it is by obedience to that law upon which it is predicated.
as well as
D&C 132:5 For all who will have a blessing at my hands shall abide the law which was appointed for that blessing, and the conditions thereof, as were instituted from before the foundation of the world.
The devil's great lie is that this is not true. In the premortal life, Satan wasn't trying to take away the agency of man by forcing men to choose what was right. He was trying to take away the agency of man by offering salvation without responsibility. He was trying to change the law that was irrevocably decreed before the foundation of the world. That law is a statement of what agency really is.
It is that we can choose our blessings by our actions. God does not grant blessings outside of what people actually choose. We have the agency to decide exactly what blessings we receive. It is complete agency.
If God chose to bless some but not others based on a reason other than the choices of his children, that would be giving man less agency. Perfect agency is represented in freedom to choose blessings by our actions, rather than having God determine them for us on our own behalf.
Satan's plan was not to force everyone to do good, but to take away the agency of man by taking away this perfect ability for man to choose his blessings. Under Satan's plan our blessings are granted not according to our agency, but in spite of our actions. It is salvation without responsibility.
This model of agency has ramifications for government. The government has no right to be redistributing wealth by force. That lies completely outside the role of proper government and tramples on the inalienable rights of man, which are actually nothing more than a form of the same right of agency that the war in heaven was fought over. If the war in heaven was fought over this agency. This ability for all to choose equally for ourselves is an inalienable right. It comprehends and overshadows the inalienable rights explicitly mentioned in the declaration of independence as each of them is nothing more than an illustration of the right of agency.