The "scientific" answer: Something blew up and turned into the world. Nobody knows where did that something get from. Then life appeared by pure chance, and instead of dying right away, evolved into something really complicated and incomprehensible for some reason.
The "religious" answer: God created all of this. Nobody knows why or what for. Nobody knows who or what god is. That's just about it.
Is it just me or is something so terribly wrong with both of these, that it would be very likely that the truth lies not somewhere in between, but rather somewhere far, far away from these two?
It's unlikely that anything plausible could be deduced with our current knowledge, but if anything, I'd say that it's probably that evolution of some sort actually took place, but it was driven by some forces that are completely outside of our knowledge now, and perhaps these very forces are referred to as "god" by religious people. It is very hard to imagine that all of this just created itself by accident, so it's probable that it actually has some meaning. It is also pretty obvious that something is terribly "wrong" with this world, in particular that it contains a lot of contradictions which mess up reasoning. For example, good and evil are so mixed up that it's pretty much impossible to remove all evil without removing all good as well. Sort of yin-yang applied in practice. It's even impossible to clearly define both good and evil, although it's also obvious that both exist.
To understand the world would mean understand ourselves, as we're a part of the world. To understand ourselves, we need to resolve all of that contradictions so our reasoning becomes consistent. While we have contradicting concepts interchange each other (like good and evil), we are dealing with contradictory system where everything could be proven from the same premise.
And it doesn't look like we got any closer to that during past few thousand years. Not a good sign at all. But then again, a thousand years is but a moment for the universe. Right now, I can only hope it happens someday. Or else it would be much better if this world never existed in the first place.