A suitable statement that illustrates the difference between a scientific law and a scientific theory is:
"A scientific law, such as the law of gravity, describes the predictable behavior of falling objects: they always fall towards the Earth at a constant acceleration. In contrast, the theory of gravity explains why this happens, detailing the underlying principles of mass, spacetime, and the gravitational force."
This statement clarifies that the law provides a consistent description of an observable phenomenon, whereas the theory offers an explanation of the mechanisms behind that phenomenon.