While there is ample scientific evidence that the entire earth was NOT flooded, there are also biblical and spiritual reasons this did not happen. I find it likely that a great flood DID occur--certainly one large enough to impress upon the primitive people who lived in Noah's age. Before man learned how vast the world is (and that it is round), would not a flood large enough to wash out a valley or settlement seem very large indeed? Oral histories featured in the old testament, handed down over the ages by mouth, very likely were based upon some factual events.
Jesus came to our world to reveal the great truth of a loving Father in Heaven and the brotherhood of man. Where in Jesus' teachings and revelations does one find an angry, brutal God, willing and capable of slaughtering every man, woman and child in a great flood? In the light of Jesus' teaching, we can see that God would never do such things. The story of Noah is a reflection of a more primitive understanding of God. Primitive man was awe-stricken by power--especially the apparent arbitrary, yet spectacular forces of nature. He was not yet ready to embrace the concept of a loving Father.
God does not change. You need to go back and read the Bible much more carefully. God has a righteous and holy wrath against sin. Jesus warned of the coming wrath.
Matthew 24:37-39 For as were the days of Noah, so will be the coming of the Son of Man. (38) 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, (39) and they were unaware until the flood came and swept them all away, so will be the coming of the Son of Man.
Matthew 3:7 But when he saw many of the Pharisees and Sadducees coming to his baptism, he said to them, “You brood of vipers! Who warned you to flee from the wrath to come?
Matthew 12:34-37 You brood of vipers! How can you speak good, when you are evil? For out of the abundance of the heart the mouth speaks. (35) The good person out of his good treasure brings forth good, and the evil person out of his evil treasure brings forth evil. (36) I tell you, on the day of judgment people will give account for every careless word they speak, (37) for by your words you will be justified, and by your words you will be condemned.”
Matthew 5:22 But I say to you that everyone who is angry with his brother will be liable to judgment; whoever insults his brother will be liable to the council; and whoever says, ‘You fool!’ will be liable to the hell of fire.
Matthew 5:29-30 If your right eye causes you to sin, tear it out and throw it away. For it is better that you lose one of your members than that your whole body be thrown into hell. (30) And if your right hand causes you to sin, cut it off and throw it away. For it is better that you lose one of your members than that your whole body go into hell.
Matthew 7:21-23 “Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but the one who does the will of my Father who is in heaven. (22) On that day many will say to me, ‘Lord, Lord, did we not prophesy in your name, and cast out demons in your name, and do many mighty works in your name?’ (23) And then will I declare to them, ‘I never knew you; depart from me, you workers of lawlessness.’
Matthew 8:11-12 I tell you, many will come from east and west and recline at table with Abraham, Isaac, and Jacob in the kingdom of heaven, (12) while the sons of the kingdom will be thrown into the outer darkness. In that place there will be weeping and gnashing of teeth.”
Matthew 11:21-24 “Woe to you, Chorazin! Woe to you, Bethsaida! For if the mighty works done in you had been done in Tyre and Sidon, they would have repented long ago in sackcloth and ashes. (22) But I tell you, it will be more bearable on the day of judgment for Tyre and Sidon than for you. (23) And you, Capernaum, will you be exalted to heaven? You will be brought down to Hades. For if the mighty works done in you had been done in Sodom, it would have remained until this day. (24) But I tell you that it will be more tolerable on the day of judgment for the land of Sodom than for you.”
Luke 13:3-5 No, I tell you; but unless you repent, you will all likewise perish. (4) Or those eighteen on whom the tower in Siloam fell and killed them: do you think that they were worse offenders than all the others who lived in Jerusalem? (5) No, I tell you; but unless you repent, you will all likewise perish.”
and many more passages...