That's true, and the one place where our knowledge is the thinnest is the origin of life, the origin of the first cell. It wouldn't surprise me if ultimately, it were shown that an intelligent designer was at work at the very beginning. (I find arguments based on "fine tuning" of the laws of physics more persuasive.) But there is evidence that the first first eukaryotic cells (cells with nuclei, as opposed to the much simpler bacteria) evolved from bacteria. It's been shown that mitochondria (the parts of the cell that process energy) had their origin in cyanobacteria. So the first eukaryotic cells originated as symbiotic relationships between different kinds of bacteria.
I should clarify my own point of view here, by the way. I am a theistic evolutionist. I believe God created life by creating a universe where evolution can happen.
“It’s been shown that mitochondria (the parts of the cell that process energy) had their origin in cyanobacteria.”
You mean it’s been observed in the lab under controlled conditions?