a Five Doves reader asked me in an email who I thought Methuselah represented. here is my opinion.
Methuselah is like Jared, in that he embodies a certain Bible concept. a human expression of a certain prophetic truth. Jared is the human expression of the Descending. read this in 1 Thessalonians 4:16.
Methuselah's name means Man of the Dart, Javelin, Missle. he represents the End of the Age, our Age, the Age of Missles. he is patriarch 8, but dies out of order. he is the last generation to die, prior to the Flood. he lives 969 years, longer than any other recorded Bible lifespan. all triangle numbers added through the 17th triangle number (153) = 969. this might mean that Methuselah is the Last of something as the 153 (mega) fish of John 21:11 are the last Catch.
Noah is the generation that lives in two Ages. Pre and Post Deluvian. the thing that stands between the two ages is the Destruction, which Noah is safely protected from. he 'rides it out' so to speak.
my gut feeling is that there actually is a certain person on the earth, that when they die, currently, in our timeline, then the Flood starts, which is the Tribulation period, like Methuselah who maybe died the day the rain started. this person may be a christian leader, I don't know, and that concept could easily be wrong. John the Baptist was a type of Elijah and the Lord said he 'was' Elijah if you had faith to believe it. same deal.
I think Genesis Five is the timetable from Adam to the End of our Age, Methuselah. he may actually represent the Church Age, the longest. Noah represents the Resurrected/Raptured out generation of saints who were alive prior to the Flood, saved from the Flood, and come back to the Post Flood Age to rule with the King Jesus, over the earth, just as Noah and his sons/daughters-in-law repopulate the recovering earth. that living generation is combined with the Dead in Christ to form a certain group.
I speculate that as with Nehemiah, some are appointed governors, etc. these are the leaders, the 153 'mega' fish that Peter dragged to shore.
I think this is the Resurrection of the Dead that Paul is striving for, mentioned in Philippians 3:11-12. a position in this group.
those are my opinions only.