Life before Life -- and After

Premortal Life
God has spirit children in the same way He has mortal children. "The inhabitants [of the worlds] are begotten sons and daughters unto God." (D&C 76:24) They are not begotten of God, but rather begotten unto Him. His spirit children, those born into spirit bodies before the worlds were created were conceived and born in the same way. I am a son of my father, who begat me, and also my grandfathers, who did not.

We were given agency. "In the Garden of Eden, gave I unto man his agency." (Moses 7:32) Eden represents our life before we came to Earth. It was perfect. It was glorious. We walked and talked with God. And, we had the ability to choose, though we were "innocent." A child is innocent, but can disobey.

All of the children of God committed some transgression in our innocence, except One. Some were enticed by others, some did it willingly so they could leave the presence of God, and "pass through sorrow," though we didn't know what "sorrow" was at the time, being innocent.

Satan is the leader of a special group of spirits who wanted what could not be had -- experience without agency, Good without evil, virtue without vice, light without darkness, health without sickness, and pleasure without pain. Unless there is an opposite, there is no existence. Temperature only exists because there is cold in opposition to hot. Light only exists because there is more or less of it. These spirits used the gift of agency they were given to choose darkness. They did not keep their "first estate" and therefore cannot move on.

Birth
Moving on to the "second estate" means to come to Earth, obtain a physical body, and be tested "to see if they will do all things whatsoever the Lord their God shall command them." (Abraham 3:25) This step required a commitment, a covenant that we made directly with our Father in Heaven -- that we would obey Him. Those who would make this commitment were allowed to come to Earth and be born into a physical body, while those who refused to make this covenant were cast out and became the Devil and his angels. This is the "war in Heaven." We were all cast out (except Christ). We are all cast down to the Earth: Satan, evil spirits, good spirits, angels, and even Michael, the Archangel. The difference is that those who made the covenant come with a physical body, while those who refused are just spirits.

Now, we have choice in a different way, outside of the presence of God. Interestingly, the requirement for returning to our Heavenly Home is exactly the same as it was that brought us to Earth in the first place: Baptism -- the covenant and promise to keep the commandments of God. The first one was made with our Father in Heaven, but in mortality our covenant is with Christ. Those who refuse this simple ordinance will not be able to return, they will have another place prepared for them, where they do not have as many choices, having more boundaries. The more they abused their choices on Earth, the more boundaries they will have. There are those who will completely and utterly go against their promise made prior to birth who will be cast out with Satan. Each chooses his level of glory by his level of obedience.

Jesus saves all
Christ is the only One who did not transgress the laws of God either in the First or the Second Estate. He was not cast to Earth because of being unfit for Heaven, rather He came willingly, to save the rest of God's children. Who are the children of God? All. All means all and all is all all means. This includes those who chose not to make either the first or the second covenant. This means those who are "a law unto themselves (Romans 2:14), who completely refuse to obey the Father. He saves even them from utter destruction because He "descended below all things." (D&C 88:6) He withstood all the temptations of Satan with no armor or help, and never transgressed a law. He loved the ones who tortured Him. He gave them a chance at life, and even saves them from themselves.