When talking to creationists and calmly explaining the process of evolution by natural selection there inevitably comes a time when I am interrupted and asked to give an evolutionary explanation for the origins of life and the universe itself. When I am unable to do this the creationist imagines they have made some sort of profound point and with a relieved expression shuts down their mind for fear of permanent contamination. But the glaring error on the part of the presumptuous victor is that evolution never claimed to explain the origins of life.
Evolution explains the diversity of life, not it's origins. Evolution is the change in inherited traits of a population of organisms through successive generations. It makes no claims about how these populations of organisms came to be, only an adequate and scientifically supported collection of facts that explain change. Though many naturalistic theories abound in the question of life origins, the most intellectually honest answer to the question is that we don't know. It doesn't mean we will always remain ignorant about this mystery, it just means that presently there is not enough evidence to grant provisional assent to a particular theory.
We'll get into the details of natural/sexual selection as well as theories to explain life's origins. We'll also explore transitional fossils and the truth behind the reliability of radiometric dating. But for the purposes of this post it is important that you understand the true claims of evolution. If you are employing the argument that because evolution does not explain the origins of life and therefore it is incomplete then stop. If you hear someone employing this argument you now know the truth and can set the record straight. Kind thoughts to you all.