Most theology is done from the perspective of a committed believer, one who has faith in the dominant texts, prophets, and revelations of a particular religious tradition. Theology also attempts to be a philosophical or even scientific enterprise. How theologians manage to merge the two competing tendencies gives rise to varying approaches to theology overall.
A very common trend in theology is known as natural theology. Whereas the default religious perspective accepts the truth of the existence of God and basic dogmas handed down by tradition, natural theology assumes that one can begin from a default position of no particular religious belief and argues to the truth of at least some (already accepted) religious propositions.
Thus, natural theology involves starting from the facts of nature or discoveries of science and using them, along with philosophical arguments, to prove that God exists, what God is like, and so forth. Human reason and science are treated as the foundations of theism, not revelation or scripture. An important assumption of this work is that theologians can prove that religious beliefs are rational through the use of other beliefs and arguments already accepted as rational themselves.
Once one accepts the arguments of natural theology (with the most common being design, teleological, and cosmological arguments), then one is supposed to be persuaded that the particular religious tradition best embodies the conclusions already reached. There is always the suspicion, however, that even though those engaged in natural theology say that they began with nature and reasoned to religion, they were influenced by more traditional religious premises than they let on.
The use of natural theology has in the past given rise to the popularity of Deism, a theistic position based upon the preference of natural reason over sacred revelation and directed at a watchmaker god which created the universe but may not be actively involved in it anymore. Natural theology has also at times been heavily focused on theodicy, the study of reasons for why evil and suffering are compatible with the existence of a good and loving god.
Going in the other direction is the theology of nature. This school of thought accepts the traditional religious method of assuming the truth of religious scriptures, prophets, and traditions. It then proceeds to employ the facts of nature and discoveries of science as a basis for reinterpreting or even reformulating traditional theological positions.
For example, in the past Christians characterized the universe, as created by God, according to their understanding of nature: eternal, unchanging, perfect. Today science is able to demonstrate that nature is instead very finite and always changing; this has led to reinterpretations and reformulations of how Christian theologians describe and understand the universe as Gods creation. Their beginning point is, as ever, the truth of the Bible and Christian revelation; but how those truths are explained changes according to our developing understanding of nature.
Whether we are talking about natural theology or the theology of nature, one question keeps coming up: do we give primacy to revelation and scripture or to nature and science when trying to understand the universe around us? These two schools of thought are supposed to differ based upon how the question is answered, but as noted above there are reasons to think that two arent so far apart after all.
It may be that their differences lie more in the rhetoric used than in the principles or premises adopted by the theologians themselves. We must remember, after all, that being a theologian means being defined by a commitment to a particular religious tradition. Theologians are not disinterested scientists or even mildly disinterested philosophers. The job of a theologian is to explain, systematize, and defend the dogmas of their religion.
Both natural theology and the theology of nature can be contrasted, however, with something called supernatural theology. Most prominent in some Christian circles, this theological position rejects the relevancy of history, nature, or anything natural altogether. Christianity is not the product of historical forces, and faith in the Christian message has nothing to with the natural world. Instead, a Christian must have faith in the truth of miracles that occurred at the outset of the Christian church.
These miracles represent the workings of God in the human realm and guarantee the exclusive, absolute truth of Christianity. All other religions are man-made but Christianity was instituted by God. All other religions focus on the natural works of humans in history, but Christianity is focused on the supernatural, miraculous works of God who exists outside of history. Christianity True Christianity is uncontaminated by man, sin, or nature.