The nature of our origin is important to who and what we are. This is because from a Biblical perspective we are special creations of God. We were created for a purpose. From a purely naturalistic and evolutionary perspective, we are nothing but cosmic accidents without any purpose whatsoever. So, the question of origins gets at the heart of who and what we are. Are we special creatures created for a purpose, or just cosmic accidents? The difference between these two makes for a big distinction.
Biblical Creation is based on the history of the Bible. That history includes creation around 6,000 years ago and a global flood around 4,400 years ago. Both of these would have been supernatural acts of God, so any effort to explain the world around us by purely naturalistic means would result in age estimates there are many times larger than they really are. This is the primary problem when it comes to dating what we see on this planet.
The fact is that the Big Bang to man evolutionary story is fundamentally atheistic. The ideas on which it was based have their roots among 18th-century atheists and deists. Modern ideas about universal common descent evolution, in particular, predate Charles Darwin and was being discussed by atheists including Charles Darwin's grandfather Erasmus Darwin. In fact, Charles Darwin got his ideas about universal common descent from reading his grandfather’s writings. You do not even have to look that far back to see the atheistic influence in this story. All you have to do is look at the reaction to intelligent design, or any suggestion of intelligent involvement in the process. Proponents of the Big Bang to man evolutionary story like to stress that there was no planning involved but that everything we see is just a result of unintelligent totally naturalistic forces. Yes, not everyone involved in creating it has been an atheist, but an atheistic perspective is abundantly clear.
This may come as a surprise to some people, but creationism is an alternative to naturalism, not evolution. Both creationism and naturalism are philosophical starting points for developing theories about the history of the world and universe. The Big Bang to man story is what you get when you try to explain the universe by totally naturalistic forces and exclude God from your reasoning as a starting condition. Biblical creation on the other hand not only allows for the consideration of God but requires God as an integral part of it. So, ultimately the question of origins is a question about whether or not God is taken into account when trying to understand the evidence.
There are several reasons why all this matters. The first is the logical fact that whether or not you include God when you try to explain the world around us has a profound influence on the conclusions that you come to. Furthermore, where we came from is a critical part of who and what we are. If we are just cosmetic accidents, then nothing is special is lost when you slaughter millions of unborn babies or even full-grown adults. However, in the Biblical account of our origin is true then we are created in the image of God, and we are special indeed and the slaughtering of our fellow human beings is a crime against God. Finally, Jesus himself spoke of both the creation and the Genesis flood as real history. So, the very credibility of Jesus Christ is at stake in this issue. There is no room for compromise, either God created the world, or the world created itself. Which position you take affects how you see the world around us in the very evidence you are studying.