It seems that just Being, the sheer fact of existence, that there is something rather than nothing, already inspires a wonder akin to religion. But - as in my comment about the Kingdom of God in the last answer - Jewish and Christian traditions are also prepared to challenge what 'is' for the sake of what could be.

In brief, I regard love as a more decisive focus of meaning than death. In terms of Heidegger's argument, this is because I think he misdescribes the importance of the deaths of others and focuses exclusively on my relation to my own death. But, in reality, the deaths of others have a more urgent and immediate impact on our lives than the purely notional knowledge that I too will one day die.

Interpretation is a task that we repeatedly have to take up and start again from the beginning, Sisyphus-like. But, as Camus said, we must always imagine Sisyphus happy, and this is not so difficult when it's a matter of texts that reveal important truths about being human.

At a theoretical level, I think a naturalist approach to religion is just asking questions I'm not interested in. They're perfectly legitimate in their own terms, but they don't address the actual experience of how one or other aspect of religion becomes existentially meaningful to us in our actual lives. The fact that we ourselves are the subject of investigation makes all the difference.

In a sense these are questions that most people ask themselves to some extent. They become philosophical when asked with a persistence and rigour that pushes past conventional or evasive answers. It's nothing to do with acquiring a technical facility in an academic discipline.

Barth's approach tears up any possibility of dialogue between faith and unfaith or between theology and other human sciences. Theology just says what it says on the basis of scripture, and that's that.

But why should a religious person be interested in a work like Heidegger's that many regard as the epitome of nihilism? For a start, because Heidegger forces us in a way that few philosophers do to really think through the seriousness and all-encompassing nature of our mortality.