If I understand well you are proposing the following explanation:
The Flood was a geographically local ordinary (non-miraculous) event that “wiped the globe of all image bearers at the time (minus Noah’s group)”, and in this sense it was global.
This was exactly the first explanation I proposed in the thread “My theory about the Flood”.
So why did I withdraw from it?
Because there is no geological evidence of a local flood that had been capable of flooding the first city-states in Sumer all together and destroying a population of hundreds of thousands Image Bearers. Additionally, as @george rightly claims, there are many features of the Genesis’ Flood which do not fit with any ordinary local flood.
Therefore it seems to me necessary to invoke a miraculous event which we believe as we believe the main miracles in the New Testament: On the basis of trustworthy witnesses, and not because there are materially preserved traces.
This is a very good point!
I also think that “spreading word of this purpose/function of mankind” was the primeval vocation of the first Image Bearers, or in the beautiful words from N.T. Wright quoted by @Kathryn_Applegate in her article:
“This pair (call them Adam and Eve if you like) were to be the representatives of the whole human race, the ones in whom God’s purpose to make the whole world a place of delight and joy and order, eventually colonizing the whole creation, was to be taken forward.”
In this sense we can say Adam and Eve and each Image Bearer shared sort of universal Priesthood.
Nonetheless subsequently to the state of generalized corruption and violence before the Flood apparently God considered it more convenient to proceed as follows:
-
At the end of the Flood He Himself directly transformed all the creatures sharing a human body on earth into Image Bearers, the same way as He created Adam and Eve and others (Genesis 1:27, 2:24, 5:1-2, 6:2-4]); it is the moment referred to in Genesis 9:6.
-
He entrusted Noah and his family to spread His Revelation, mainly: 1) God made mankind in His Image (“into a special covenantal relationship with himself”) and commanded them male and female to keep the sanctity of marriage (“called…Adam and Eve…into a one-flesh unity with each other”). 2) He is capable of removing sinners from earth (Flood as demonstration). 3) Nonetheless He is merciful and lets them on earth so they have time to atone and reach eternal life (Rainbow as sign).
It is the content of the covenant in Genesis 9:8-17. -
He called Abraham to become founding father of a chosen people with mission to keep God’s Revelation alive till the Incarnation of His Son (God’s authentic Image) “Jesus Christ, the ultimate source of blessing to all the nations.” (Genesis 11: 31, 12).