Ad Majorem Dei Gloriam (To the Greater Glory of God)
From: Genesis 6:5-8; 7:1-5, 10
The spread of wickedness
 The Lord saw that the wickedness of man was great in the earth, and that every imagination of the thoughts of his heart was only evil continually.  And the Lord was sorry that he had made man on the earth, and it grieved him to his heart.  So the Lord said, “I will blot out man whom I have created from the face of the ground, man and beast and creeping things and birds of the air, for I am sorry that I have made them.”  But Noah found favour in the eyes of the Lord.
 Then the Lord said to Noah, "Go into the ark, you and all your household, for I have seen that you are righteous before me in this generation.  Take with you seven pairs of all clean animals, the male and his mate; and a pair of the animals that are not clean, the male and his mate;  and seven pairs of the birds of the air also, male and female, to keep their kind alive upon the face of all the earth.  For in seven days I will send rain upon the earth forty days and forty nights; and every living thing that I have made I will blot out from the face of the ground."
Boarding the ark
 And Noah did all that the Lord had commanded him.
6:1-8. From the very beginning, evil and sin spread in tandem with the growth of mankind. We can see this in the episode of Cain and Abel and the same point is being made, somewhat obscurely in this account, which bears traces of the ancient Yahwistic tradition.
6:5-8. The severity of these words shows just how corrupt mankind had become. There is also a lesson here about the absolute sovereignty of God, who has power to wipe mankind off the face of the earth.
God’s original plan when he created man seems to have been a failure--hence his decision (couched in very human terms) to destroy what he has made. But that is not going to happen: mankind will be saved through the fidelity of one man, Noah; and the earth will he populated again after the flood. We see two themes coming in here which have a high profile in the Bible: the first is that God loves everything he creates, and his interventions (even in the form of punishment) are always aimed at man’s salvation; the second is that the righteous man, or a small remnant of faithful people, brings about the salvation of all mankind. It is in this sense that the Fathers also see in Noah a figure of Christ, because through Christ’s obedience God’s mercy reaches every human being.
Jesus recalled this episode of Genesis to warn us that we need to be always vigilant and ready to receive him at his second coming: "As were the days of Noah, so will be the coming of the Son of man. For as in those days before the flood they were eating and drinking, marrying and giving in marriage, until the day when Noah entered the ark, and they did not know until the flood came and swept them all away, so will be the coming of the Son of man"’ (Mt 24:37-39).
6:9-8:22. The flood happens because man rejected the law of God (this process began with Adam and Eve). God punishes man’s disobedience by undoing the order of nature that he himself had established for man’s benefit. Thus, the waters above and below, which God had wisely separated from the earth (cf. 1:7), now invade the land in full force (cf. 7:11). The result is a return to chaos, and mankind is on the point of disappearing. The situation calls for a new beginning following on a severe purification. The bible is offering us here an impressive lesson about the destiny of mankind when it turns its back on God and rejects the laws that are stamped on creation itself.
In many religions, not only those of the Near East, we can find stories to do with the destruction of mankind (or a large part of it) in pre-history -- be it by water or fire or sonic cataclysm. Most of these stories tie in with belief in malevolent gods and man’s fear of them, or with his sense of a need or purification. For example, certain Sumerian and Babylonian legends had features very like those in the Bible account of the flood. But there is a fundamental difference: the Bible depicts the blood as a consequence of mankind’s sin, and as a new starting point from which the true God, the Creator of the world and of man, can advance his plans of salvation through a remnant; from that remnant will later emerge Abraham, the father of the chosen people.
7:4. On the seven days’ downpour St Ambrose, following 1 Peter 3:20, which speaks of God’s patience at that time, explaining that "the Lord made available a time for penance, because he prefers pardon to punishment" ("De Noe et arca", 13, 42).
7:5. In contrast with Adam’s disobedience, which was the source of all evil in the world, Noah followed the Lord’s instructions exactly, even in the smallest details (cf. 6:22). For his obedience Noah will he exalted as one who put his faith in God into practice: "By faith Noah, being warned by God of events as yet unseen, took hold and constructed an ark for the saving of his household; by this he condemned the world and became an heir of the righteousness which comes by faith" (Heb 11:7).