Is there a God? Does sin cause problems on earth?

The real answer is this. No one knows (at this point in time) how the universe was created. Scientist don't say they know that God created the Universe, simply because there is a gap in science.

If there is a gap in science, an unknown, scientist say there is an unknown. Let's keep searching! Now that is exciting stuff. Scientist to not assign supernatural causes to things they can't explain.

Which brings up another point. It's easy to see why people grasp at religion when science can't explain things. Where are we from? Oh shit, not sure. Hmmmm, must be, God did it! Yes, that's it! I have the answer! Wow!

What happens when we die? Oh shit, not sure. Hmmmm, we either go to heaven or hell, per God! Ah ha! I have the answer again! God sends us to heaven or hell. I'm so glad I know these things with complete certainty!

In the past, (in the not so distant past) when there was a drought and people were dying, what happened? Oh shit, God is mad at us, we need to repent. Oops! Wrong. They didn't have modern science back then, so they simply assigned a supernatural reason for the drought. God was not mad. We exist on a living planet which is orbiting the sun, which is what creates weather. It's called, earth science.

The Black Plague.. Hmmm... we don't have science to figure this out, so let's just say, God is mad. Yes! That's it. God is mad because of our sin! Human sin (egotism here) is the cause of the Black Plague! We have the answer. Errr.... wrong again!

"No one in the 14th century seems to have considered rat control as a way to ward off the plague, and many people began to believe only God's anger could produce such horrific displays. There were many attacks against Jewish communities.[45] In August of 1349, the Jewish communities of Mainz and Cologne were exterminated. In February of that same year, Christians murdered 2,000 Jews in Strasbourg.[45] By 1351, 60 major and 150 smaller Jewish communities had been destroyed.[46]" ----http://en.wikipedia.org/wiki/Black_Death

The human body? Where did it come from? The estimated age of the earth is around 4.54 billion years. It takes a lot of time for life through evolution to take place.

For starters, you can Google using these search terms: Natural selection, evolution, Darwinism. I typically look at the Wikipedia entries as Wikipedia is very accurate.