There have been many answers to the question received so far from atheists, but most have been disheartening. It isn't because I may or may not disagree with them. They are disheartening because none of them describe a worldview. They each take on one aspect of understanding the world, namely the scientific enterprise, but leave so much more out of their answers.
I've explained before that a worldview is the way one sees and interprets the way the world works. It's basically a framework for understanding and interpreting the various facts we encounter in our lives. That's why any attempt to outline a worldview must account for at least the following five things. I'd like to go over each of these quickly.
1. One's understanding of originsThe concept of origins is central to interpreting many things in the world. Some of the key questions of origins include: Where did we come from? Why is there something rather than nothing? What is reality? Where do good and evil find their foundations? These are all crucial when seeking to make sense of people and situations. For example, if you hold that human beings bear God's image, you are going to have a different perspective on the nature and dignity of issues like assisted suicide, abortion, and the equality of all people.
2. One's understanding of rationalityReason is a key component of understanding our world, so providing an account of rationality and why or if we can rely on our reasoning skills is important. How does reason work in the world? Is it a reliable way of knowing things? How can one know that?
3. One's understanding of purposeAnother primary factor in interpreting the world is identifying if there is any kind of purpose to our world and if so, how can one discover that purpose. The understanding of telos—that there is a design or an ultimate end to the cosmos, humanity, or even to each individual will play a huge part in how one values others, the environment, and many other areas.
4. One's understanding of moralityMorality and its grounding has been something I've written about quite a bit, but every worldview must have some kind of understanding of what morality is and where it comes from. Societies simply cannot function without certain agreed upon notions of right and wrong. Even if your worldview holds that objective morality doesn't exist, it must be expressed and integrated into your explanation of how society determines values.
5. One's understanding of ultimate endsLastly, every worldview has some kind of account of what our ultimate ends are. Is there a reality beyond this world? Do we cease to be when we die? How does one discover this end and how does this life relate to any our ultimate end? This along with the question of purpose are key to helping us decide how to act in various circumstances.
One of the reasons I hold to the Christian worldview is it answers each of the five questions and does so in a way where each area is integrated with the others to form a coherent whole. Christianity gives a single picture of the world, where each of these five areas makes sense with 1) the way we observe our world to work and 2) makes sense with each other. They follow naturally from one to the next. Without an integrated, coherent worldview, values and judgments become confused or contradictory.
So, what's your worldview? Have you thought about each of these five areas? Does your worldview not only account for each, but does it do so in a way that isn't ad hoc, or happenstance?