Life of course uses existing chemicals and of them them is silicon. It is a very large part of soil since soil is partially made up of sediments which are often almost all silicates. But the problem for believers in dirt magic, like you, is that the percentages are incredibly far off. Where silicon is gong to be one of the most common elements in dirt, very possibly second after oxygen, it is observed as only a trace element in the human body. So man is clearly not made of dirt, or mud, or soil as in your myths.