Once again, your words reveal your ignorance of history. Academics by the end of the 17th century were beginning to question the tale of creation we find in the first chapters of the Bible, though the power of the Church meant little was published during the lifetimes of the philosopher/naturalists. The French naturalist, Jean Baptiste de Lamarck, wrote in the early 1800s about changes in species. Darwin was not alone in proposing what became known as the Theory of Evolution, Alfred Russell Wallace laid out a very similar idea at the same time as Darwin. We know more about Darwin today owing to societal differences in 19th century England -- Charles Darwin came from a 'better' family than Wallace and had more connections with the academic world of the day.
Every theory begins with "wild speculations" which are formalised into a hypothesis that is then tested by experimentation and data collection to the point where a scientific theory is formulated.
Don't do much reading outside of your religious tracts, one can see by your words posted here. The
"preachers and teachers" who work with the Theory of Evolution in their research are not searching for the origin of life, that is a different field of science. The scientific term for origin of life is
abiogenesis, the process by which living organisms came from inorganic or inanimate substances.
Unlike creationists, those who actually do research, commonly called
scientists, accept that they don't know for sure the exact process by which life originated. That is why, at this time, there are multiple hypotheses that are being tested.