PMW 2022-071 by Kenneth L. Gentry, Jr.
The early generations of men following Adam live to enormous ages of centuries. According to the genealogy in Gen. 5 Adam lived to be 930; Seth 912; Enosh 905; Kenan 910; Mahalalel 895; Jered 962; Methusaleh 969; Lamech 777; Noah 950.
Then in the Gen. 11 genealogy after the Flood, longevity begins dropping: Shem lives to be 600; Arpachshad 438; Shelah 433; Eber 464; Peleg 239; Reu 239; Serug 230; Naho 148; Terah 205. Later Abraham lives to be 175 (Gen. 25:7) and Moses 120 (Deut. 34:7). Moses’ age was remarkable in its day (Deut. 34:7), and he even declared that a strong man might live to be 80 (Psa. 90:10).
Critical scholars point to these as evidence of Genesis’ mythological character. But these ages are set in a strongly historical context. Some well-meaning scholars suggest that the “years” in view are much shorter than our year. But the Gen. 5 chronology will not allow that, while the later genealogy in Gen. 11 obviously assumes standard year lengths as it points to declining longevity.
Postmillennialism
By Keith Mathison
The promises of the gospel offer hope of a brighter future for the families and nations of the earth. Mathison’s an optimistic eschatology supported by biblical, historical, and theological considerations.
See more study materials at: www.KennethGentry.com
These are literal ages from a remarkable era of history following the original creation. Three factors are apparently involved in allowing these life spans.
First, God intended for man to subdue the earth (Gen. 1:28) and wanted him to spread out through the world (cp. Gen. 11:8). Therefore, he allowed longer ages for earlier men to enhance population growth and geographical spreading.
Second, this probably also results from what scientists’ would call “natural causes.” Adam and Ever were originally created perfect and without any genetic defects. But as time went on, defects began multiplying and reducing longevity.
Third, apparently the climate changed after the Flood for we also see smaller animals and larger plants when compared to some of the large dinosaurs of the past.
AS IT IS WRITTEN: THE GENESIS ACCOUNT LITERAL OR LITERARY?
by Ken Gentry
Presents the exegetical evidence for Six-day Creation and against the Framework Hypothesis. Strong presentation and rebuttal to the Framework Hypothesis, while demonstrating and defending the Six-day Creation interpretation.
See more studies at: www.KennethGentry.com
Apparently, long lives are expected to return as the gospel conquers the world bringing in righteousness on a remarkable level. God tells Isaiah of this day:
“No longer will there be in it an infant who lives but a few days, Or an old man who does not live out his days; For the youth will die at the age of one hundred And the one who does not reach the age of one hundred Will be thought accursed. (Isa. 65:20)
In the height of the postmillennial advance of Christ’s kingdom, men will turn from their evil and destructive conduct, wars will decline and cease as peace takes root, medical research will expand without the encumbrance of evolutionary mythology, and God will pour out his covenantal blessings.
Postmillennial Worldview 
No. This is a final gasp of Satan allowed by God after a long era of righteousness and peace prevailing.