Theory: The physical universe is inherently deterministic. God created it by creating a singularity with very precise, exact, and carefully chosen parameters, and then just let it run on its own for billions of years, so that it could explode and develop time and space and light and stars and planets and rivers and elephants, in a completely deterministic way that was pre-programmed into the original parameters.
Spiritual entities (such as God and angels and human spirits) exist outside of the physical universe, but can affect the physical universe, and are themselves not deterministic. About three million years ago, God selected several of the bipedal mammals which he had designed the universe to eventually produce and bound them to spirits which he'd created. And at that point, humans were created, complete with free will and the ability to alter the course of the otherwise deterministic universe.
Any thoughts or opinions?