The origin of life has, in fact, not been settled. I have my own theories on how life emerged, and it has nothing to do with a deity. But for many people, and for many scientists in particular, the issue is not settled at all.
In addition, natural selection (the IDer's favorite thing to take aim at) is a theory of how life emerged and how it evolves over time. Being a theory, it must be challenged and tested. Natural selection has stood up very well to any and all challenges, and has been elaborated upon and modified accordingly since 1859. I am convinced that natural selection is responsible for how life evolves. But a whole lot of people are not because they simply don't get it or because their faith fills in the blanks, allowing them the trouble to actually think.
The faithful somehow think that evolution, and more specifically "science" in general, are belief systems. They are not. Science in particular is a standardized process of developing a hypothesis about why a thing works, testing that hypothesis, and releasing the results of the tests so that others may test the hypothesis as well. As these hypotheses form, many contribute to a bigger domain called a theory. In turn, that theory can be challenged and tested as well. None of this effort aims to find the "meaning" behind this or that process - that is for the religions and philosophers to hash out. Indeed, my studies have lead me to a view of the Universe; science does not provide "The Meaning" for me, it fills in the bits and pieces, and I assign meaning to the ever evolving picture.
Religions cannot be tested in this way. That is why people who believe in them have faith. Faith is simply not good enough for me, and it hasn't proven good enough for millions of people since about 400 years ago.