Genesis 6

Genesis 6:3:
Then the LORD said, "My Spirit will not contend with man forever, for he is mortal ; his days will be a hundred and twenty years."

The days are shortened for man.

Genesis 6:4:
The Nephilim were on the earth in those days—and also afterward—when the sons of God went to the daughters of humans and had children by them. They were the heroes of old, men of renown.

It cannot be denied that the Hebrew expression rendered "sons of God" in our Bibles is used exclusively of angels elsewhere in the Old Testament. It appears in Job 1:6 and 2:1, where angels are obviously in view. Satan was among them. The Septuagint renders it "angels of God" in these two places also.

Genesis 6:13-14:
So God said to Noah, "I am going to put an end to all people, for the earth is filled with violence because of them. I am surely going to destroy both them and the earth. Make thee an ark of gopher wood; rooms shalt thou make in the ark, and shalt pitch it within and without with pitch.

With all the evil that is going on in the world today, God has not put an end to the world. How much more evil was going on back then? The decription in Matt 24;38 suggest they "were eating and drinking, marrrying and giving in marriage, until the day Noah entered into the ark." They appeared to be a normal active society. Yet, God says they were filled with violence. But Gen 6:5 clarifies. every imagination of the thoughts of his heart was only evil continually." As any drug addict can tell you, the habit is in the mind. The Hebrew word for "violence" mean "vicious dealings, mistreatment, wrongful imaginings, cruelty." The fruit being produced in society was a fruit of the peoples minds and hearts.

"Pitch" is the same word translated "atonement" (Lev 17:11) and illustrated the atoning work of Christ, which keep out the judgements of water.

Noah by nature deserved to be destroyed because of his sin against God. “But Noah found favor [or grace] in the eyes of the Lord” (Gen. 6:8). God graciously provided him and his family the ark—a means through which they could escape from the flood of God’s judgment against sin. Likewise, in our natural condition we deserved to perish in hell, but God graciously provided us a savior in the person of His Son through whom we can escape from the fire of God’s wrath in hell. Noah and his family did not deserve the ark. We did not deserve Christ either. We did not deserve heaven; we deserved hell. God gave us the exact opposite of what we deserved. -Biblical Spirituality

Genesis 6:18:
"But with thee I will establish my covenant; and thou shalt come into the ark, thou, and thy sons, and thy wife, and thy sons wives and thee."

Noah, like Adam, becomes with this the representative of humanity. The covenant becomes God's gift to Noah of the grace, mercy, and law of God. Mankind must look to Noah (as to others) as their father in the covenant of God.

Genesis 6:14:
Make thee an ark of gopher wood; rooms shalt thou make in the ark, and shalt pitch it within and without with pitch.

"Pitch" is the same word translated "atonement" (Lev 17:11) and illustrated the atoning work of Christ, which keep out the judgements of water.