I just happen to have written an article that addresses whether the theist must view God as a person. The article's in response to "Backyard Church" and will be coming out soon.

The semantic choice of labels isn't so philosophically interesting. What's important is the concept that's commonly been associated with the position of those who've called themselves theists and monotheists. This is the idea that God is the supreme being and creator and ruler of the universe. To distinguish theism from deism, God is supposed to intervene miraculously in nature. God is also supposed to reveal himself to us, allowing for divinely inspired scriptures. Then there's the belief in the monotheistic religions that God will judge us after we die.

All of those beliefs imply that God is a person. The concept of a sovereign ruler amounts to an analogy with human kings. As creator or designer, God is compared to an architect, craftsman, or potter.

Suppose God isn't a person, but a force, a dimension, or an emptiness about which nothing positive can be said. How would theism contrast with atheism in that case? Atheists are happy to talk about ultimate forces, materials, and dimensions. It's treating them as personal that atheists think is wrongheaded. And why would an atheist disagree if God amounts to nothing at all?

So it's God's personhood that's the sticking point, which is crucial to the vulgar, exoteric conception of God, but not so much to the esoteric one of the intellectual elites. The philosopher's God is a metaphysical abstraction which ends up entailing atheism.

Descartes' proofs of God's existence don't work, as even undergraduate philosophy students are taught these days.