A true Christian will never attack the Bible or question the veracity of its record. It will be accepted as historical, factual, chronological, as well as spiritual. Study The Genesis Flood by scientists Whitcomb and Morris. Those who knowingly reject the truth of Noah's Flood basically call God a liar, since the Bible record is very clear (Genesis 6:5-7;11-13;17). How can anyone is his right mind and with full comprehension claim that this is a localized flood?
5 And GOD 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.
6 And it repented the LORD that he had made man on the earth, and it grieved him at his heart.
7And the LORD said, I will destroy man whom I have created from the face of the earth; both man, and beast, and the creeping thing, and the fowls of the air; for it repenteth me that I have made them...
11 The earth also was corrupt before God, and the earth was filled with violence.
12 And God looked upon the earth, and, behold, it was corrupt; for all flesh had corrupted his way upon the earth.
13 And God said unto Noah, The end of all flesh is come before me; for the earth is filled with violence through them; and, behold, I will destroy them with the earth...
17 And, behold, I, even I, do bring a flood of waters upon the earth, to destroy all flesh, wherein is the breath of life, from under heaven;and every thing that is in the earth shall die.