8 Wherefore, how great the importance to make these things known unto the inhabitants of the earth, that they may know that there is no flesh that can dwell in the presence of God, save it be through the merits, and mercy, and grace of the Holy Messiah, who layeth down his life according to the flesh, and taketh it again by the power of the Spirit, that he may bring to pass the resurrection of the dead, being the first that should rise.Both the Book of Mormon and the New Testament make reference to Christ being the "firstfruits." I had always just assumed that this meant the first fruit of the harvest, since Christ was the first to be resurrected from the dead. I was only half right; the firstfruits are literally the first fruits of the harvest, but they are also tied to the law of Moses. The children of Israel were commanded to bring a sheaf of the firstfruits to the altar prior to making their animal sacrifice. The animal sacrifice is obviously symbolic of the Savior, but so are the firstfruits, which were to be brought before the Lord before an acceptable sacrifice could be made.
9 Wherefore, he is the firstfruits unto God, inasmuch as he shall make intercession for all the children of men; and they that believe in him shall be saved.
10 And because of the intercession for all, all men come unto God; wherefore, they stand in the presence of him, to be judged of him according to the truth and holiness which is in him. Wherefore, the ends of the law which the Holy One hath given, unto the inflicting of the punishment which is affixed, which punishment that is affixed is in opposition to that of the happiness which is affixed, to answer the ends of the atonement—
The fall brought both spiritual and physical death to Adam and all of his descendants. Each of us is born into this life, separated from the presence of God, and into a mortal body that is subject to death. The atonement overomes both of those deaths for all men. Notice that because of the atonement "all men come unto God." This is necessary because "there is no flesh that can dwell in the presence of God" except through the power of the atonement.
What does it mean to "dwell" in the presence of God? It have always though that it meant "to live", but it could also mean to linger or stay. These verses seem to be saying that without the atonement, men would not even be able to come back to God's presence to be judged. This may be similar to those who cannot live the law, and therefore cannot abide a celestial glory.
Given the context, it also seems that resurrection is a necessary step before we can be taken back to his presence. When Jesus appeared to Mary outside the tomb, he told her "I am not yet ascended to my Father," was that because he needed to have his resurrected body first? (I am also curious as to why she was not allowed to touch him, but that may be tangential to the topic.)
Verse 8 says that Christ is "the first that should rise." How can this be, seeing that others had been brought back from the dead previously such as the daughter of Jairus and Lazarus for example? The difference is that these were brought back to a mortal state. This is not a true resurrection because after being risen from the dead, they still had imperfect, unglorified, mortal bodies with blood flowing through their veins. It wasn't until Christ conquered death once and for all that it was made possible to live again and never die.