God shut Noah and his family into the ark (Gen. 7:16) so that they were saved. All this, we saw, prefigures the work of Jesus. Our Lord Jesus is the ultimate ark. The righteous man runs into Him and he is safe (Prov. 18:10). When we enter into Christ we escape the wrath of God.
The Genesis flood is not primarily a meteorological or a seismological event or whatever other scientific description you may choose. The flood is primarily a theological event, and the weather and the geology are God’s tools in that process!
As Christians we actually consider the whole of life as theological. As Christians we should not think that theology and science are in conflict. Theology and true science are in fact great allies. But who would be the senior partner?
In Europe during the High Middle ages, schools of higher learning called theology the “queen of the sciences.” They understood that the various branches of learning required an overarching standard. That standard to them was the Bible, because the Bible is the source of all truth and therefore the starting point for learning. “The fear of the LORD is the beginning of knowledge” (Prov. 1:7).
In our day the theory of evolution and its associated agendas have managed to move theology to the lunatic fringe, but for any serious and thinking Christian this constitutes a serious attack on the authority of our Bible and therefore an attack on faith.
The Bible makes after all important claims with respect to the origin and the creation of the world and the universe. The Bible makes important claims about man who is said to be made in the image of God. The Bible also asserts that all the animals, birds and insects were each made according to their own kind and not by a process of evolution. The Bible speaks of sin and judgement in response to man’s rebellion against God, and the Bible claims that a universal flood was the first great indication concerning God’s universal wrath on man’s sinfulness. This is clearly seen in the pronunciation made in Gen. 6:5-7.
Now clearly the claims of evolutionary teaching do not agree at all with the Scripture, and so we have to make up our mind in this regard. Do we take the claims of Scripture seriously or not? If the Bible is simply fiction, then the next question would be, “but can we trust fiction?”, and “ if Genesis isn’t strictly speaking true, then what else may we discard in the Bible“? John McArthur has correctly pointed out that, “ Scripture, not science, is the ultimate test of all truth. And the further evangelicalism gets from that conviction, the less evangelical and more humanistic it becomes.”
So, as we get back to our text, at this point in the history of Genesis, we have seen that God’s patience with mankind has come to an end. God is determined to make an end of all mankind by means of a universal flood : Gen. 7:17,18 The flood continued 40 days on the earth. The waters increased and bore up the ark, and it rose high above the earth. The waters prevailed and increased greatly on the earth and the ark floated on the face of the waters.”
Many think that the flood mentioned here was perhaps simply a severe local flood in the Mesopotamian valley. But this is not what the Bible indicates. If it was simply a local flood, Noah could have simply escaped to another part of the world to escape from this flood . Instead, he is commanded to build an Ark of gigantic proportions!
According to Gen. 6:15 the Ark was 140 meters long, 23 metres wide and 14 metres high - longer than a soccer field and higher than a 4 storey building. It had three decks, and a capacity of approximately 15000 tonnes. In modern terms it would be have held over 500 standard shipping containers. It is a huge vessel by modern standards. We ask, how is this possible? We forget that engineering techniques, tools and machines of ancient man were far more advanced than we are ready to believe. Not long after the flood, the Egyptians were able to cut huge granite blocks and transport and construct massive, precision built pyramids. In the 3rd Century B.C. the Egyptian pharaoh Ptolemy IV Philopator had a huge wooden boat built. It was 130 meters long, powered by three banks of oarsmen, being able to carry 4000 soldiers.  The ark was a much simpler construction. It was built to float !
The Bible indicates that there was a universal flood. There are about thirty expressions in Genesis chapters 6-9, which indicate that the Flood was universal. This flood was associated with significant seismological activity which caused the fountains of the great deep burst forth and in conjunction with torrential rains. Remember that this was God’s doing! This catastrophic event was so severe that one would not recognise the earth today from the earth as it was then! Some creation scientists believe that a single continent was broken up as the result of this flood. They maintain that the post flood earth developed an entirely new geology, with huge sediment deposits that included billions of fossils, plants , animals , insects that were trapped in torrential mud which quickly formed into sedimentary rock. Approximately 75% of the continental surface is sedimentary rock, which indicates that there was huge movement of gravel , sand and silt - all the result of these huge masses of water moving over the face of the earth.
I have found it astounding to learn that even the sedimentary layers that form the uppermost parts of Mt. Everest are composed of fossil bearing, water-deposited sediment. Incidentally, the Indian tectonic plate is pushing up the Eurasian plate and enormous tectonic movement has not only produced the highest mountain in the world , but it is also true to say that Mt. Everest is growing. The fact that fossils are found near the top of Mt Everest is significant, for it indicates that this must have been submerged and flooded at some time in history. The Geology of the world is always changing.
One of the most fascinating insights into recent thinking about geological processes has been provided by Mt. St. Helens (USA), which erupted in June 1980. It has been awesome to see how quickly those sediment strata formed. Three separate eruptions produced sedimentary-type layers hundreds of feet thick. One of these was a hurricane velocity deposit that produced thousands of thin laminations up to 25 feet thick. The third eruption was a lava flow, which turned into a hot mud-flow as it crossed the Toutle River. This hot mud flow not only diverted the river, but carved a 17 mile long series of canyons (up to 140 feet deep) in a matter of hours. They call it the Little Grand Canyon of the Toutle River."…. so , canyons don’t need millions of years to form.
Having said all this I must humbly confess, that I (and all of us) do not know how God exactly brought the flood about, and what exactly happened as a result. We just weren’t there. Nobody except Noah and his family were there, and all our efforts to understand or explain what God did then will not change the fact that the Bible says that there has been a universal flood , and that it primarily happened in response to man’s evil and corrupt nature. God did it, and He did it in the same way in which He always works – by His supernatural power, ordering and commanding nature to obey His awesome commands. Who will not fear God as you hear this?
The Flood lasted for forty days, and we are told that at the end of this time the mountains of the earth were covered to a depth of more than 6 meters (Gen. 7:19). It was 150 days after the rain had begun, and 110 days after the rain and springs had ceased to pour out water that the Ark was able to touch land on the mountains of Ararat (Gen. 8:4). From there another 10 weeks again passed before the mountain tops became visible, and then another 21 weeks passed before Noah and the family and the animals could leave the ark. Noah was almost on the ark for a year! And so God accomplished what He set out to do . He has once judged the earth with a terrible judgement.
We have every reason to believe that there was such a universal flood. Significantly and finally we observe that Jesus believed the flood to be an historical and therefore accurate account , for He did not contradict it when He affirmed in Matthew 24:38-44:
 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 were unaware until the flood came and swept them all away, so will be the coming of the Son of Man.  Then two men will be in the field; one will be taken and one left.  Two women will be grinding at the mill; one will be taken and one left.  Therefore, stay awake, for you do not know on what day your Lord is coming.  But know this, that if the master of the house had known in what part of the night the thief was coming, he would have stayed awake and would not have let his house be broken into.  Therefore you also must be ready, for the Son of Man is coming at an hour you do not expect.
Significantly the Lord Jesus connects the universal flood with the universal judgement at the end of all days when He shall come again. Why should we believe in the Genesis account as accurate and historical ? Because Jesus understood the OT as history. Jesus also regarded Adam, Eve and Noah as historical people.
So did the apostle Peter, who spoke of the Flood, and we note that he too assumed it to be a worldwide flood, because he said,
“By these waters also the world of that time was deluged and destroyed” (2 Pet. 3:6).
He then also compares it to the present heavens and earth, which are reserved for fire. He is not saying that only one localized area would be burned by fire in the final judgment . . . he implied that just as the Flood was global, so the final judgment of the earth by fire will be global. If only part of the human race were destroyed by the Flood, the major point made in Scripture of all humanity being corrupt, violent, and having hearts inclined toward evil would be lost.
One can understand why atheistic evolutionists would want to re- interpret the history of the earth in terms of great ages and evolution, rather than trusting in the biblical account of Creation and the Flood. According to their belief system they must get rid of God, and Satan has provided a very effective tool to persuade biblical illiteralists. It has in fact become a new faith system, and it must be said that biology and much of what is called science today goes far beyond what we would call ‘scientific’. Much of it is in fact speculation and speculation is the atheist version of faith. We need to ask an important question : "Who among finite men has the authority to say that the earth is 4.5 billion years old? 
Well might the words of Job 38:4 be repeated: “Where were you when I laid the foundation of the earth? Tell me if you have understanding.”
The Flood reminds us that God has judged the earth once. And we have seen that Jesus uses the flood account as a reminder to us that there will be a second destruction of the earth, not by water, but by fire.
So, here are some important questions to answer:
- What is your faith position?
- How will you escape from the coming wrath ?
Again, we can say that God is so good. He has provided an ark for us ; this time not a ship, but a person. His own Son. The righteous run into the Name of Jesus and they are saved.
 Quoted in : 15 Reasons to take Genesis as History : Creation Ministries International ,p.25
 Tas Walker (PhD in Mechanical Engineering ; BSc in Earth Science) : The Genesis flood (2006) Creation Ministries ; The Genesis Flood : Fact or Fiction , p.6
 Tas Walker : The Genesis Flood, p.28 ( References and notes)
 https://answersingenesis.org/age-of-the-earth/how-old-is-the-earth/ Prior to the 1700s, few believed in an old earth. The approximate 6,000-year age for the earth was challenged only rather recently, beginning in the late 18th century. These opponents of the biblical chronology essentially left God out of the picture. Three of the old-earth advocates included Comte de Buffon, who thought the earth was at least 75,000 years old. Pièrre LaPlace imagined an indefinite but very long history. And Jean Lamarck also proposed long ages.However, the idea of millions of years really took hold in geology when men like Abraham Werner, James Hutton, William Smith, Georges Cuvier, and Charles Lyell used their interpretations of geology as the standard, rather than the Bible. Werner estimated the age of the earth at about one million years. After Lyell, in 1899, Lord Kelvin (William Thomson) calculated the age of the earth, based on the cooling rate of a molten sphere, at a maximum of about 20–40 million years (this was revised from his earlier calculation of 100 million years in 1862).13 With the development of radiometric dating in the early 20th century, the age of the earth expanded radically. In 1913, Arthur Holmes’s book, The Age of the Earth, gave an age of 1.6 billion years.14 Since then, the supposed age of the earth has expanded to its present estimate of about 4.5 billion years (and about 14 billion years for the universe).