Do fundamentalist Christians believe in the theory of Gravity?
They do. They even accept germ theory and atomic theory. Only when an idea affects their emotional need to be a special creation do they care. That is why they attacked heliocentrism. That is why they attack evolution. And that is why they will attack neuroscience. Edit: A theory is an explanation of a phenomena and a framework for future work. The theory of gravity is currently Einstein’s theory of general relativity. Laws are postulates, simple statements that describe something. In this case Fg = Gm1m2/r^2.