Contracted to a span

1. The Trinity and the Incarnation are often classified as paradigm-cases of theological paradox. I wouldn't go that far myself, although they are undoubtedly mysterious. 

2. Since Christianity is a revealed religion, we take revealed truths as our starting-point. That can sometimes be explicated and supplemented by philosophical analysis and extrabiblical analogies, but revelation enjoys preeminence in Christian epistemology. That outlook is epitomized by Anselm's "faith-seeking-understanding" approach.

3. Critics of Christian theology regard this as special pleading. They like to keep everything simple, rationally transparent, and commonsensical. However, this isn't just a question of theological orientation, but philosophical orientation. On the one hand are reductionists. They're impatient with mystery and complexity. They embrace Occam's razor. They incline to physicalism, nominalism, eliminative materialism, mathematical finitism and fictionalism, &c. 

The opposite outlook is reflected by thinkers like Leibniz, Cantor, and the principle of plenitude. Whatever is possible (or conceivable) is in some sense actual. Whether true or not, the multiverse reflects this outlook. 

Newtonian physics is commonsensical whereas quantum mechanism and relativity are counterintuitive. Likewise, Cantor made the actual (abstract) infinite intellectually respectable, with his diagonal proof. 

4. Ironically, disdain for mystery can reintroduce mystery at a different level. The unitarian theology of Maimonides and Al-Ghazali eschews the complexities of Christian theology, yet their metaphysically simple deity, having no analogy in creation, becomes an ineffable, unintelligible blink. 

5. I've explored different ways to model the Trinity and Incarnation. I'll reiterate one illustration, then consider two others. Suppose computer scientists develop artificial intelligence. Suppose they create a video game with artificially intelligent virtual characters. Suppose the video game designer creates a character who represents himself. At one level, his virtual counterpart has the properties of a computer simulation. His mode of subsistence is the same as other virtual characters who populate the game. He exists inside the game. 

At another level, his virtual counterpart shares the mind of the inventor. That character exemplifies a being outside the game. Its knowledge of the game transcends the game. Its perspective surpasses the viewpoint of other virtual characters who only exist within the world of the game. That's one analogy for the hypostatic union.

6. It isn't necessary to know how something can be true to know that it's true. And it isn't necessary to know how something can be true to be warranted in believing it. We can begin with paradigm examples. Whatever is actual is possible. 

Consider how abstract objects like numbers interface or intersect with the physical world. Abstract objects are timeless and spaceless. Yet the universe contains finite exemplifications and approximations of abstract mathematical structures like Pi, Euler's number, the Golden ratio, and the Fibonacci number. That's another analogy for the hypostatic union. 

6. Finally, there's such a thing as family resemblance. That isn't merely physical but often psychological. Parents are present in their children insofar as their kids share parental character traits. Sometimes a kid takes after his father while another kid takes after his mother. And some kids take after both parents. My own psychological makeup alternates between my father and my mother (as well as my grandfathers). My default setting is my father, but depending on the social setting, I can instantly switch to my mother's temperament. In a sense, they exist in me and I in them. Two persons in one person. One person in two persons. Three persons in all. That's a mundane shadow of the Trinity and the Incarnation.