The
theory that is currently used to
explain where
life came from by
scientists. Basically, that life came into existence from non-living
chemicals.
While it's extremely unlikely that they can ever show that it's where we came from, they can show that it's possible. And they are slowly doing just that. They haven't done it yet, but they've made basic building blocks of our type of life from inorganic chemicals.
Here's a simplified list of the steps in the abiogenesis theory:
Note that there are other
smaller steps that have been left out.
Most creationists think it simply goes from chemicals to bacteria. They're wrong.