I may as well begin this blog by starting with one of the biggest clashes between science/common-sense and biblical 'history': Noah's Ark.
The story is presented as history. I know some Christians who believe it happened as the bible said it did. But let's consider the details.
In Genesis 6, God is apparently very precise about the size of the ark: 300 cubits long, 50 cubits wide and 30 cubits high (about 140 metres long, 23 metres wide and 13.5 metres high) - that's a total volume of 43470 cubic metres.
Now, science tells us that there are about 30 to 50 million species of animal, even supposing that three quarters of these are marine animals, and can therefore survive the flood, that still leaves us with at least 7.5 million species to go on the ark. And, of course, two of each unclean species and seven of each clean species are required. So more than 15 million animals have to be fitted on the ark.
That leaves only 0.002898 cubic metres per animal. And even if Noah was able to find one animal per minute, 24 hours a day, 6 days a week (he was righteous in the eyes of the Lord, so must have kept the sabbath), it would take 33 years to fill the ark.
I could go on. The point is this: the events described could not have taken place as described. Perhaps there was an ark and a lot of animals were taken on it, but there is no way that the flood could have been worldwide as other land animals clearly survived the experience even though they were not on the ark.
The problem this introduces is that it clearly shows that some of the stories in the bible, which are presented as history, are merely stories. They may have some roots in history, but time and embellishment have changed them to such a degree that the actual history is lost. But this leads us to question every story in the bible - if Noah's ark is just a myth then what about Moses, King David and so on, what about the things Jesus is reported to have done?
More than that, it leads us to challenge one of the fundamental aspects of belief for many Christians - the divine inspiration and infallibility of the bible.