[Cicero]

I'm a pre-modern, I suppose (which certainly qualifies me as a conservative). I see no difficulty in believing in the existence of God through the use of natural reason. (Biblical revelation is necessary to go beyond that, of course.)

As Aquinas points out (see Gilson especially on this), God is existence itself. "I AM that I AM." As long as you have that principle to start with, all this fossicking about looking for some foundation to build on is pretty much wasted time. That's why Heidegger's idea that being depends on something like human death seems pretty deluded to me.

[bdeaner]

That's why Heidegger's idea that being depends on something like human death seems pretty deluded to me.

I can see how one could arrive at that interpretation of Heidegger, but I do not interpret Heidegger that way. Heidegger's existential analytic of Da-sein is a methodological choice, not the conclusion of his analysis. I think, later, he regretted this methodological approach, and this may be why he abandoned the project of Sein und Zeit (his promised third part was never completed). Heidegger's regrets on this score are probably best represented in his critique of Sartre in "Letter on Humanism." Worth reading.

Anyway, Being does not depend on human recognition of death. Just the opposite. The condition of possibility for the human recognition of death (ontic level of analysis) is that nothingness is the basis for Being (the ontological level of analysis).

Heidegger always begins with ontic description in order to disclose the ontological dimension. That's his hermeneutic method.

As for theology, it is important to recognize that Heidegger was a German who began his studies in the seminary. And one of his central influences was Meister Eckhart. So, Heidegger's ontology is quite similar, in some respects, to Eckart's negative theology. John Caputo has written a very good book on this, titled The Mystical Element in Heidegger's Thought.