More widely: Science of what has been written or preached in religious traditions as belonging to the faith of the religion.

My own position, being an atheist, is that in the end theology is a science of nothing: Its subject does not exist, so far as I can tell, which is far enough to know that all the proofs of the existence of God that I know of either are false or prove nothing remotely like what religions have taught.

Still, many intelligent men in the past - before the rise of science, especially - have been much concerned with theology, and some of this is interesting, especially when it is concerned with things that do exist, such as human beings, moral norms, what it is to have virtue etc.

Even so, from my own point of view much of theology is nonsense or false, and has done much harm, and while it makes sense to study what has been written or preached in religious traditions this is best done in a real scientific spirit, and not based on a faith that one cannot prove, that one has little or no good evidence for, that seems mostly based on wishful thinking or following authorities, and that contradicts science in many ways, as is true of all theology I know of.