The bible claims that God created the heavens and the Earth in six days. In calculating the begats listed in the bible, Christian fundamentalist claim that the Earth and indeed the entire universe is less than ten thousand years old.
But why did it take God six whole days to do it. Being all powerful, couldn't He have accomplished it in six minutes, or six seconds, or six picoseconds? Here's why I think it might have taken all day for God to complete each of the ordered tasks before him.
On the first day he created light, and light created he it. But light in its very fundamental nature has a finite speed to propagate the universe. So even though the universe was created almost instantly, God had to place also the radiant beams of photons outward from their origin precisely to match their distance so that the distant stars would at once be visible from the Earth, which was to be created the next day.
It took all of the second day to separate the sky from what would become the ground. God could have created the Earth instantly, but He wanted to take care in crafting this planet to appear much older than it was. So he placed fossils in the ground and molded the rocks and strata into layers so that silly geologists would later be fooled into thinking that the age of the rocks was much older. This was deliberate and in harmony with God's divine plan.
On the third day, he started shaping the land so that the oceans would have their place and the mountains and dry land would appear. This He accomplish by volcanism, er, His divine will, to create large plates of granite which could be moved around to form continents, mountain ranges, and frightening earthquakes to show His power later on. He carefully fashioned these mountain ranges so that they appeared to have been formed over millions of years; even though they were not. Apparently, this didn't take all day so he added grasses, plants and trees. This was before any living thing appeared in the oceans. That wouldn't occur for another two days.
Curiously enough, God didn't create the stars or the sun and moon until the fourth day and started the earth spinning and revolving around the sun; so we could have calendars and know when it is night time. That took all day!
The fifth day was when sea creatures and birds appeared. It is a bit puzzling that the oldest fossils man has found are of sea creatures. God must have taken great care on the second day to create this illusion so that one day, archaeologists would be taken down such an erroneous path of reasoning that they might just forget this whole curoisity/knowledge thing and stick to the wisdom of the holy scriptures for all the answers any of us would ever need. These beings are commanded to be 'fruitful and multiply'. I always found that phrase to be a bit redundant; like being "frightend and scared". Why did it take a whole day to do that when just the day before, He created all the stars and planets? Thank God it was Friday!
On the final day of God's work of creation, the animals were made. Perhaps as an afterthought, human creatures were added to the mix because they look so much like Him. Everyone is told, like the birds and fishes, to be fruitful and multiply. And God gives Man the mandate to 'fill the earth, and subdue it.' Very good, God.