It is based on obedience and what is in the heart. One scripture that brings this out is:
"For we labor diligently to write, to persuade our children, and also
our brethren, to believe in Christ, and to be reconciled to God; for
we know that it is by grace that we are saved, after all we can do."
(2 Nephi 25:23)
It has been stressed that it is not "we are saved because of what we do" but rather "after all we can do" ("The Gift of Grace", President Dieter F. Uchtdorf, 2015 April Conference, Sunday morning session). What can "we do"? We can love God with all our heart, mind, and soul (Matthew 22:26-40). We can then show that love through obedience to the commandments (John 14:15). We can repent of our sins ("After All We Can Do", Elder Claudio D. Zivic of the Seventy, 2007 October General Conference). What it really boils down is to strive to measure up to the stature of Jesus Christ (Ephesians 4:11-13) by overcoming the "natural man":
"For the natural man is an enemy to God, and has been from the fall of
Adam, and will be, forever and ever, unless he yields to the enticings
of the Holy Spirit, and putteth off the natural man and becometh a
saint through the atonement of Christ the Lord, and becometh as a
child, submissive, meek, humble, patient, full of love, willing to
submit to all things which the Lord seeth fit to inflict upon him,
even as a child doth submit to his father." (Mosiah 3:19)
The LDS beliefs align with Universalism such as is expressed in these Articles of Faith:
11 We claim the privilege of worshiping Almighty God according to the
dictates of our own conscience, and allow all men the same privilege,
let them worship how, where, or what they may.
12 We believe in being subject to kings, presidents, rulers, and
magistrates, in obeying, honoring, and sustaining the law.
13 We believe in being honest, true, chaste, benevolent, virtuous, and
in doing good to all men; indeed, we may say that we follow the
admonition of Paul—We believe all things, we hope all things, we have
endured many things, and hope to be able to endure all things. If
there is anything virtuous, lovely, or of good report or praiseworthy,
we seek after these things.
One point that may differ slightly from Universalism may be that the church itself remains politically neutral and will not allow the buildings to be used for political purposes. However members are strongly encouraged to be active in the political process.
There is no doctrine on Annihilationism that I am aware of though some opinions have been tossed about regarding it. As far as the final judgment goes there will be those that are sent to the Lake of Fire:
"30 And we saw a vision of the sufferings of those with whom he made
war and overcame, for thus came the voice of the Lord unto us:
31 Thus saith the Lord concerning all those who know my power, and
have been made partakers thereof, and suffered themselves through the
power of the devil to be overcome, and to deny the truth and defy my
power—
32 They are they who are the sons of perdition, of whom I say that it
had been better for them never to have been born;
33 For they are vessels of wrath, doomed to suffer the wrath of God,
with the devil and his angels in eternity;
34 Concerning whom I have said there is no forgiveness in this world
nor in the world to come—
35 Having denied the Holy Spirit after having received it, and having
denied the Only Begotten Son of the Father, having crucified him unto
themselves and put him to an open shame.
36 These are they who shall go away into the lake of fire and
brimstone, with the devil and his angels—
37 And the only ones on whom the second death shall have any power;
38 Yea, verily, the only ones who shall not be redeemed in the due
time of the Lord, after the sufferings of his wrath." (D&C 76:30-38)
The Eternal-Conscious-Torment belief is held by some based on the following verse while others hold to the previous verse in D&C 76.
"Therefore if that man repenteth not, and remaineth and dieth an enemy
to God, the demands of divine justice do awaken his immortal soul to a
lively sense of his own guilt, which doth cause him to shrink from the
presence of the Lord, and doth fill his breast with guilt, and pain,
and anguish, which is like an unquenchable fire, whose flame ascendeth
up forever and ever." (Mosiah 2:38)
The Bible Dictionary defines "hell" this way:
An English translation of the Hebrew word Sheol, hell signifies an
abode of departed spirits and corresponds to the Greek Hades. In
common speech it generally denotes the place of torment for the
wicked, although it has been often held, both in the Jewish and the
Christian churches, that Hades (meaning broadly the place of all
departed spirits) consists of two parts, paradise and Gehenna, one the
abode of the righteous and the other of the disobedient. Gehenna, or
Gehenna of fire, is the Greek equivalent of the “valley of Hinnom,” a
deep glen of Jerusalem where the idolatrous Jews offered their
children to Moloch (2 Chr. 28:3; 33:6; Jer. 7:31; 19:2–6). It was
afterwards used as a place for burning the refuse of the city (2 Kgs.
23:10) and in that way became symbolic of the place of torment (Matt.
5:22, 29–30; 10:28; 18:9; 23:15, 33; Mark 9:43, 45, 47; Luke 12:5;
James 3:6). Expressions about “hell-fire” are probably due to the
impression produced on men’s minds by the sight of this ceaseless
burning and are figurative of the torment of those who willfully
disobey God.
In latter-day revelation hell is spoken of in at least two senses. One
is the temporary abode in the spirit world of those who were
disobedient in this mortal life. It is between death and the
Resurrection, and persons who receive the telestial glory will abide
there until the last resurrection (D&C 76:84–85, 106), at which time
they will go to the telestial glory. In this sense the Book of Mormon
speaks of spiritual death as hell (2 Ne. 9:10–12). Hell, as thus
defined, will have an end, when all the captive spirits have paid the
price of their sins and enter into a degree of glory after their
resurrection. Statements about an everlasting hell (Hel. 6:28; Moro.
8:13) must be interpreted in their proper context in the light of D&C
19:4–12, which defines eternal and endless punishment.
On the other hand, the devil and his angels, including the sons of
perdition, are assigned to a place spoken of as a lake of fire—a
figure of eternal anguish. This condition is sometimes called hell in
the scriptures (2 Pet. 2:4; D&C 29:38; 88:113). This kind of hell,
which is after the Resurrection and Judgment, is exclusively for the
devil and his angels and is not the same as that consisting only of
the period between death and resurrection. The one group are redeemed
from hell and inherit some degree of glory. The other receive no
glory. They continue in spiritual darkness. For them the conditions of
hell remain. [https://www.lds.org/scriptures/bd/hell?lang=eng&letter=H]
