Hmmmm. I like that question, do you see the steam coming out of my ears? Let's see, what we know about knowledge. Adam and Eve were taught by the Lord in the Garden of Eden, and finally, by their decision, gained knowledge of good and evil. When they were cast out of the garden, there was an angel who taught them the gospel (whatever they did not already know). So, at this point of history mankind knew the whole plan, everything essential to return to Heavenly Father. He actually did provide this knowledge. Same situation right after the flood at Noah's time. But obviously man was not able to keep the fullness of the gospel. The problem about truth is: Not everybody likes it. And the more you sin, the less you like it. (Knowledge at school is a bit different. Like it or not, as a student you have to repeat it properly to earn a good grade.) Laman and Lemuel were taught well by their father, as I assume, and they saw angels -- but they were not willing to obey, and they and their children changed the teachings and traditions according to their taste. God sent prophets over and over to restore the knowledge which was lost or corrupted. HE did his part, but Satan and man did their part as well and will continue doing it. Nevertheless, in God's plan is a way to fix this too. If you never learned the truth because you never had the chance to do so, you will be taught in the Spirit World. And we here have genealogy and temple work to do that part which they cannot do. I believe strongly, that everybody is judged not only by his/her deeds compared to the full law of God, but according to the knowledge he/she obtained or could have obtained. So if a person lives up to his/her knowledge and conviction and is - measured to these standards - a good person, he/she will most probably accept the gospel in the spirit world, and will receive the same celestial glory as anybody who accepted the gospel during his/her mortal existence. It is only a different way towards the same goal, necessary because of Satan's and man's doing, but already in the plan of salvation! Does this make sense?