Every Son or Daughter of Adam

“‘Jesus had not finished his work when his body was slain, neither did he finish it after his resurrection from the dead; although he had accomplished the purpose for which he then came to the earth, he had not fulfilled all his work. And when will he? Not until he has redeemed and saved every son and daughter of our father Adam that have been or ever will be born upon this earth to the end of time, except the sons of perdition. That is his mission. We will not finish our work until we have saved ourselves, and then not until we shall have saved all depending upon us; for we are to become saviors upon Mount Zion, as well as Christ. We are called to this mission.’”
Joseph F. Smith, Gospel Doctrine, 5th ed. Salt Lake City: Deseret Book Co., 1939, p. 442; emphasis added.

“There is never a time,” the Prophet Joseph Smith taught, “when the spirit is too old to approach God. All are within the reach of pardoning mercy, who have not committed the unpardonable sin.”
Teachings of the Prophet Joseph Smith, p. 191; emphasis added.

I like these quotes because they emphasize the two opposing states of the final existence of man. Everyone will be either sons of salvation or sons of perdition. They will either go to heaven or outer darkness. There is no in between. Those who receive the pardoning mercy, which comes through repentance and baptism, will be saved and go to heaven.