While we could talk about the Flood, or not (and I will be answering the other question more than this part), it will be better to have the accurate version at least (of course!). Here's the actual text (which of course does not say God "killed", not exactly....), but does say some crucial aspects
few know, because people think they already have the story, but the wording is always surprising when we look more closely, in the Bible. That's an amazing quality of much of the Bible, that the wording seems to change when we look again. This happens especially in the 4 gospels. Just for the accurate version, which really changes our views on a key thing or two, here's an accurate modern translation of that Genesis 6 key passage from the NASB --
5 Then the LORD saw that the wickedness of man was great on the earth, and that every intent of the thoughts of his heart was only evil continually.
6 The LORD was sorry that He had made man on the earth, and He was grieved in His heart.
7 The LORD said, “I will blot out man whom I have created from the face of the land, from man to animals to creeping things and to birds of the sky; for I am sorry that I have made them.”
8 But Noah found favor in the eyes of the LORD.
9T hese are
the records of the generations of Noah. Noah was a righteous man, blameless in his time; Noah walked with God.
10 Noah became the father of three sons: Shem, Ham, and Japheth.
11 Now the earth was corrupt in the sight of God, and the earth was filled with violence.
12 God looked on the earth, and behold, it was corrupt; for all flesh had corrupted their way upon the earth.
13 Then God said to Noah, “The end of all flesh has come before Me; for the earth is filled with violence because of them; and behold, I am about to destroy them with the earth."
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Isn't verse 5 surprising? Let's look closely at it in several translations:
New International Version
The LORD saw how great the wickedness of the human race had become on the earth, and that
every inclination of the thoughts of the human heart was
only evil all the time.
New Living Translation
The LORD observed the extent of human wickedness on the earth, and he saw that everything they thought or imagined was consistently and totally evil.
English Standard Version
The LORD saw that the wickedness of man was great in the earth, and that
every intention of the thoughts of his heart was
only evil continually.
Berean Study Bible
Then the LORD saw that the wickedness of man was great upon the earth, and that every inclination of the thoughts of his heart was altogether evil all the time.
New American Standard Bible
Then the LORD saw that the wickedness of man was great on the earth, and that every intent of the thoughts of his heart was only evil continually.
Young's Literal Translation
And Jehovah seeth that abundant is the wickedness of man in the earth, and
every imagination of the thoughts of his heart
only evil all the day;
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I don't think people usually believe this.
They don't want or can't understand (?), often, many people, such a situation.
Where there is precisely zero love. None, not even sometimes.
Every inclination of the human heart only ever evil always.
That's....so hard to even imagine, for us, today, here and now.
Right?
What would it even be like.
That there isn't merely some evil, or merely much evil, or even merely predominate evil, but instead the fantastic and impossible-seeming situation of only evil, alone.
Only. Not anything else. Only evil, always. Only hate, murder, rape, brutality. What verse 11 says can't be a hyperbole given verse 5, but instead is the precise statement without any exageration, in order to fit with verse 5.
Actually zero love anywhere. None anywhere.
I don't think people can easily believe this, but it's what the text says.
God regretted in his heart that He had even made mankind at all.