The argument can be formulated as follows:
P1. If there is a God, he is omnibenevolent
P2. Many people do not hear about God on earth and is beyond their control
P3. God sends people to hell if they don’t believe in him
P4. An omnibenevolent being would not send anyone to hell for something they had no control of
C1. Therefore this is contradictory
C2. Therefore God does not exist
The hidden premise in this argument is that the only opportunity to hear about God is on earth. However in Latter-day thought this is not the case and in the words of 1 Peter 4:6
For for this cause was the gospel preached also to them that are dead, that they might be judged according to men in the flesh, but live according to God in the spirit.
The work of salvation for the dead is a key principle in Latter-day thought.
The destiny of the unevangelized argument rests on a hidden premise which is not true in Latter-day thought.