The concept of God is often invoked to explain phenomena. If the phenomenon is one that has a scientific explanation, then it is possible to compare the scientific merits of the two explanations, one based on science and the other or God or, more generally, on faith.
The nature of what constitutes a good scientific theory is not universally understood. As a result, sometimes reasoning based on faith is seriously promoted as scientific. Scientists tend to judge scientific theories on their accuracy, simplicity, and suggestiveness. Any faith-based theory that is represented as scientific should be subjected to those three criteria. We will illustrate this point with some very simple, perhaps trivial, examples.
Not all phenomena can be successfully explained by science. In some cases a scientific explanation is possible but not yet available. In others, such explanations will never exist. In still others, people will have different opinions as to whether and when such explanations will be developed.
In cases where science does not (yet) have a needed answer, what are we to do? We scientists use scientific theories as long as they seem to do the job. In the same spirit, we can use arguments based on faith so long as they seem to work, and as long as we keep in mind the assumptions made.
Without this kind of approach we would be severely limited in what we could do. Much of the work of many professions, including engineering, deals with human nature, for which we have no scientific theories. In addition, science itself rests on assumptions about nature and the rational thought process that are not, in the final analysis, provable. Finally, we scientists are ourselves humans, and so our activities "off the job" require dealing with matters for which no scientific theory will work.