I read somewhere that since Moses died at 120 years of age that is the longest anyone can live. Is there any scriptural or writings of general authorities that would substantiate this?
In relation to Moses death, there is no scriptural evidence specifying that man will only live 120 years as a result of his death. When we dig into scripture we find different scenarios which present different thoughts that we can further look into.
In the Old Testment, Adam is specified to have lived 930 years. However, in our Teachings of the Presidents of the Church: Joseph Smith; Chapter 8, we read, “Adam … was the first man, who is spoken of in Daniel as being the ‘Ancient of Days’ [Daniel 7:9], or in other words, the first and oldest of all.” Seth the son of Adam is said to have lived 912 years old. Enoch was 365 years old, while Methusaleh was 969 years old.
In Genesis 6:3, we read, “And the Lord said, My spirit shall not always strive with man, for that he also is flesh: yet his days shall be an hundred and twenty years.” This provides some evidence possibly that men will only live to 120 years old. In spite of this verse though, as previously mentioned, we see man who lived well beyond 120 years of age.
In our present day, the oldest man is claimed to have lived 122 years of age. His name was Mr. Magomed Labazanov from Russia.
When we look further into scripture, we recognize in the Book of Mormon, 3 Nephi 28:2-3, “And they all spake, save it were three, saying: We desire that after we have lived unto the age of man, that our ministry, wherein thou hast called us, may have an end, that we may speedily come unto thee in thy kingdom.
And he said unto them: Blessed are ye because ye desired this thing of me; therefore, after that ye are seventy and two years old ye shall come unto me in my kingdom; and with me ye shall find crest.”
These men lived only to 72 years of age before they were received into the kingdom of God. In light of this verse, we can compare Psalms 90:10, which states, “The days of our years are threescore years and ten; and if by reason of strength they be fourscore years, yet is their strength labour and sorrow; for it is soon cut off, and we fly away,” and emphasizes a relatively similar age for men, 70 years, maybe 80 years (however, we have prophets who have lived nearly five score years).