People tend to assume that theologians must all have faith. Not necessarily. Theologians are the father of jurists, and grandfather of scientists. They all formulate hypotheses, and prove — from existing evidence — an all-encompassing theoretical framework that is logically coherent.
If one manages to use Plato’s theory, or any other tools, to prove the fundamental coherence of all things Christian, s/he is a qualified Christian theologian. If one attempts to prove the inherent coherence of all custom, and comes up with a logically consistent theory, s/he is a jurist — although her / his jurisprudence is not a law in itself, and there is no guarantee that a jurist would not break any law. If one seeks to prove the inherent causality or correlation amongst all planets or diseases, s/he is an astrologist or biologist.
History develops from theology to jurisprudence, and from jurisprudence to science. The most difficult part, rather than proving or falsifying the validity of any specific fact, is how one justifies the inherent coherence from a large body of seemingly contradictory evidence. Most people think that the world is in a natural state of chaos, and there is no all-encompassing law. Apparently, the existence of law in itself is a matter of faith…
Theology, jurisprudence and science can all by their nature be viewed as faith, yet, technically speaking, it is not inconcievable that the practitioners — theologians, jurists and scientists — do not necessarily have faith or can shelve their faith in the theories they have invented. This is not dissimilar to lawyers who, when defending criminals, use the same set of evidence with the prosecutors but under a different explanatory framework, so as to make the lay jury unable to judge which explanation is more convincing — what Max Weber refers to as Wertuteilsfreiheit (value-freedom, freedom from value judgement, or ethical neutrality).