start by accepting the truth
As is often the case, the barmaid nails it:
"How would you define theology?"That's it. That's precisely it.
"You start by accepting the truth of several propositions: there is a loving Creator God, for example, who has communicated with us via perfect and immutable holy scripture. Then you try to figure out ways to defend those propositions from accusations of implausibility, and iron out any inherent contradictions."
That's why all the people who hector Dawkins, and to a lesser degree Hitchens and Dennet and Stenger and Harris, for not addressing arcane theological points don't get it. Those points have nothing to do with the inherent truth of the propositions. They are post hoc attempts to justify an already assumed truth. They examine nothing, they prove nothing, they only shore up (so to speak) a building with no foundations.
Theology doesn't start by asking "Is there God?" It starts by saying "There is God." It's begging the question in both senses of the phrase - it assumes the truth of the underlying proposition, and it cries out for a response of "Yes, but what if there isn't?" (Or, "how do you know, huh?")
Not that it will - or can - answer, beyond "There just is, take my word for it. I just know."
And that's why it's pretty words and pictures - or sound and fury - but always, always, signifying nothing.
Those who want to examine that central proposition don't need to read their Aquinas (or whoever). Aquinas (and the rest) aren't looking at that proposition at all; they're building on it.
If it's not true to begin with, it doesn't matter what airy structures you build on the assumption that it is: they aren't true either. Logic and systems of thought are marvelous that way. If you accept the axiom, you can go anywhere. ("If Batman could fly -" "But he can't." "Yeah, but if he could..." "Well, sure; if he could...")
But accepting the axiom isn't proving it. It's just starting by accepting an unproven statement.
There's an old saying: Begin as you mean to go on.
Some people begin with blind acceptance. Others - don't.