The One Degree of Glory
It's interesting that, as Alma lectures his son about the resurrection and the eternal fates of souls, he describes the afterlife as being binary (and he's not just talking about the Spirit World this time):
And if their works are evil they shall be restored unto them for evil. Therefore, all things shall be restored to their proper order, every thing to its natural frame—mortality raised to immortality, corruption to incorruption—raised to endless happiness to inherit the kingdom of God, or to endless misery to inherit the kingdom of the devil, the one on one hand, the other on the other—He uses hands to illustrate his point. Hands, quite obviously, tend to come in pairs. Hands are not subdivided into several smaller hands. Alma is saying that there are only two destinations for resurrected beings—the kingdom of God and the kingdom of the devil.
However, in Doctrine and Covenants section 76, God lays out an explanation of the three degrees of glory—you know, the three separate places that righteous people can wind up. God only inhabits one of these places. So, contrary to what Alma says in this chapter, there are four final destinations for resurrected beings and two of them are neither the kingdom of God nor the kingdom of the devil. And, of course, this all gets even more confusing when you bring in Doctrine and Covenants section 131, in which Joseph Smith teaches that even the highest degree of glory, the Celestial Kingdom, is also subdivided into three different "heavens or degrees."
The more I think about it, the more I feel like the Plan of Salvation is just one long brutal game of macrocosmic Plinko.
They Aren't Not Entirely Non-Unalterable
Check out verse 8:
Now, the decrees of God are unalterable;Stop right there!
Please. Polygamy was very clearly a decree from God that was very publicly altered. The straightforward, unqualified "thou shalt not kill" decreed by God on Mount Sinai was altered in the fourth chapter of the Book of Mormon when he basically orders Nephi to kill Laban. Let's not pretend that God hasn't changed his mind about stuff and sent a few mixed signals over the centuries.
It's So Easy a Caveman Could Do It!
Picking up from where I left off in verse 8:
...therefore, the way is prepared that whosoever will may walk therein and be saved.
And now, behold, my son, do not risk one more offense against your God upon those points of doctrine, which ye have hitherto risked to commit sin.
Do not suppose, because it has been spoken concerning the restoration, that ye shall be restored from sin to happiness. Behold, I say unto you, wickedness never was happiness.The first half of this quote makes it sound like attaining salvation is a matter so simple as walking into a room. The next two verses contradict this imagery by warning Corianton that one more screw-up is a massive risk to his eternal well-being. The second part sounds like the Mormonism I grew up with. The first part doesn't.
The way definitely is prepared that whosoever will may walk therein and be saved. Except that the overwhelming majority of the world knows nothing about this way and is therefore not prepared to follow it. And even though some will walk therein and be saved, most will not—and those who have will need to walk therein by proxy to be saved on other people's behalf.
And the gospel isn't as easy as walking down a path to a destination. It's more like walking along a tightrope to a destination when the tightrope is over a bottomless pit, the destination is too far distant to be seen, and there's a series of flaming hoops to jump through to get there. Mormonism teaches people to obsess over their worthiness because any deviation from the "prepared way" could send them tumbling hopelessly into the pit, never to see the light of day again.