Some valid arguments from absurdity

Here are some curious forms of argument that I want to play with. First:

1. Doctrine D is so absurd that no one could believe D while fully realizing its absurdity, except by a miracle.
2. Someone believes D while fully realizing its absurdity.
3. So, a miracle has occurred.

Given the human capacity for believing the unbelievable, it is going to be hard to support (1) for any interesting D (except maybe: p and not p).

Let's try this:

4. Doctrine D is so absurd that no one could reasonably believe D while fully realizing its absurdity, except by a miracle.
5. Someone reasonably believes D while fully realizing its absurdity.
6. So, a miracle has occurred.

In arguments of this sort, the difficulty has shifted to (5). But we might try the following. Start by observing that a person doesn't become unreasonable simply by having a trivial belief that isn't reasonable. But to center one's life one a belief that isn't reasonable might be enough to render one unreasonable:

7. If at least one of the beliefs central to x's life is not reasonable, then x is an unreasonable person.
8. x is not unreasonable.
9. One of the beliefs central to x's life is D.
10. x fully realizes the absurdity of D while believing D.
11. So someone reaosnably believes D while fully realizing its absurdity.

The conclusions of the above arguments were that a miracle has occurred. Can we conclude that D is true? Well, we would have to look at our best explanation of the miracle. If it involves God, then we have reason to think D is true. Here's an argument that avoids the detour through miracles.

12. Doctrine D is so absurd that no reasonable person would hold D as a belief central to her life while fully realizing D's absurdity unless she knew D to be true.
13. Some reasonable person held D as a belief central to her life while fully realizing D's absurdity.
14. So, somebody knew D to be true.
15. So, D is true.

I think the big difficulty with arguments of this form in the cases most familiar to me, namely with D a doctrine from the Christian tradition, is that people who are paradigm examples of rationality, like Thomas Aquinas, do not take the doctrine to be really absurd.