My take on one reason for the flood was so that the Lord would have some righteous people through whom He could work on the earth to bring the Saviour into the world to fulfill prophesy & save mankind. For the world had become exceedingly evil. So the flood that destroyed people was actually for their salvation, as it was necessary to save them.
The Saviour is announced as the Saviour of the world, which i take to mean Saviour of all people, including those who died in the flood, and still remained in unbelief, if any. Though while they were dying in the days of the flood & realizing Noah was right, who can deny that many, if not all of them, may have repented. If not, they will receive much more powerful evidences of God with & following their own resurrection back to life.
Other than that there appears to be a lot of differences of opinions with commentators (re Gen.6:3) guessing as to what this difficult passage means & why God shortened man’s life span to 120 years. In the Psalms reference is made to 70 or 80 years.
What eternal Damnationists commentating re Gen.6:3 don’t explain, though, is the idea that if this lifespan is the only chance for salvation, why a loving God would make the lifespan much shorter, thereby giving men less time to find God. And what of those who die at ages 0 to 20? Do they not get the same chances as others living longer? Furthermore, why bring the wicked back to life, if they are totally hardened beyond even the repair of Love Omnipotent? Just to torture them before the unfeeling impotent terminator machine called god sends them to endless doom?
The same Hebrew word (OLAM, 5769) used for “forever” in Gen.6:3 also appears in Lam.3:31:
For the Lord will not cast off forever, (Lam.3:31)
32 For if He causes grief, Then He will have compassion According to His abundant lovingkindness. 33 For He does not afflict willingly Or grieve the sons of men.…
Lamentations 3:31-33 as translated above appears to contradict your interpretation of Genesis 6:3.
Alternate translations from yours, however, solve the puzzle:
JPS Tanakh 1917
And the LORD said: ‘My spirit shall not abide in man for ever, for that he also is flesh; therefore shall his days be a hundred and twenty years.’
Douay-Rheims Bible
And God said: My spirit shall not remain in man for ever, because he is flesh, and his days shall be a hundred and twenty years.
Young’s Literal Translation
And Jehovah saith, ‘My Spirit doth not strive in man – to the age; in their erring they are flesh:’ and his days have been an hundred and twenty years.
Concordant Literal Version
And saying is Yahweh Elohim, "Not abide shall My spirit in the human for the eon, in that moreover, he is flesh. And come shall his days to be a hundred and twenty years.
Rotherham Emphasized Bible
And Yahweh said—My spirit shall not rule in man to times age—abiding, for that, he also, is flesh,—Yet his days shall be a hundred and twenty years.
NET Bible
So the LORD said, “My spirit will not remain in humankind indefinitely, since they are mortal. They will remain for 120 more years.”
ISV
Then the LORD said, "My Spirit will not remain with human beings forever, because they are truly mortal, and their lifespan will be 120 years.
English Standard Version
Then the LORD said, “My Spirit shall not abide in man forever, for he is flesh: his days shall be 120 years.”
John Wycliffe’s Translation
And God seide, My spirit schal not dwelle in man with outen ende, for he is fleisch; and the daies of hym schulen be an hundrid and twenti yeer.
Brenton English Septuagint Translation
And the Lord God said, My Spirit shall certainly not remain among these men for ever, because they are flesh, but their days shall be an hundred and twenty years.
Charles Thompson Translation (of the LXX)
then the Lord God said, "My breath must not continue in these men to this age, because they are flesh; their days however, shall be an hundred and twenty years
Complete Apostle’s Bible (of the LXX)
And the Lord God said, My Spirit shall certainly not remain among these men forever, because they are flesh, but their days shall be one hundred and twenty years.
“R.V. marg. rule in. Better, according to many ancient versions, abide in…”
“…Shall not dwell (LXX., οὐ μὴ καταμείνη; Vulgate, non permanebit; Syriac, Onkelos).”
Bible Hub: Search, Read, Study the Bible in Many Languages
“Genesis 6:3 compare perhaps continue, do something continually, in modern Egyptian Arabic (SoSK lxvii {1894}, 211 f.). (1) ᵐ5 ᵑ9 ᵑ6 Onk read ידיר or (Kue) ילון abide in, dwell, — My spirit will not abide in man for ever; this best suits the context, but ידור, as Aramaism, is dubious (2) Kn De Schr RVm render rule in, supported by Zechariah 3:7 only. (3) Thes Ew Di render be humbled in, sustained by Arabic usage, but not by Hebrew (4) strive with of AV RV (compare 6 above) is hardly justified.”
Brown-Driver-Briggs Hebrew and English Lexicon, Unabridged, Electronic Database.
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And I will bless them that bless thee, and curse him that curseth thee: and in thee shall all families of the earth be blessed. (Gen.12:3)
1 Jn.2:27 But the anointing which ye have received of him abideth in you, and ye need not that any man teach you: but as the same anointing teacheth you of all things, and is truth, and is no lie, and even as it hath taught you, ye shall abide in him.
If God doesn’t save all, is it because He can’t or doesn’t want to?
“…it doesn’t say what most evangelizers of hopelessness want it to say in that regard either.”
“It is false, he maintained, to translate that phrase as “everlasting punishment,” introducing into the New Testament the concept found in the Islamic Quran that God is going to torture the wicked forever.”
“…non-Christians are punished forever for not recieving grace, which doesn’t seem very graceful to me.”
evangelicaluniversalist.com/forum/
tentmaker.org/ScholarsCorner.html
tentmaker.org/books/hope_beyond_hell.pdf
lovewins.us/