Classical theists believe that God is simple, in the sense described by the doctrine of divine simplicity. God has no parts, has no distinct essences, God's essence is God's existence, God is pure actuality, lacks any unrealized potentiality, and is just pure subsistent existence. They also say that God is not a person, and so God lacks beliefs and intentions. (Edward Feser, a Catholic philosopher has a blog where he has written lots about classical theism, for example in this nice overview.) (Here, "person" doesn't mean "human being", it's more abstract: a person is just something with beliefs and intentions, or an intellect and a will.)
My difficulty with classical theism is that by removing personhood from God, I don't see how anything of spiritual or emotional significance follows from it. God is too abstract; believing in simple-God doesn't seem any different than believing in some other abstract metaphysical theory, and I wonder why it should even be called "God". Nothing of any real difference to how I live my life immediately follow from believing in pure act or subsistent existence.
One of my atheist friends put it nicely by saying something like this: "Let's say I take the cosmological arguments seriously, and so now I believe in pure act, subsistent existence, or some absolutely simple metaphysical entity that caused everything else. I would still continue to live my life as though I were an atheist. I wouldn't believe in an afterlife, objective moral values, life would still be (cosmically) meaningless, and so on. Why would pure act or subsistent existence care about us, take interest in our actions, give our life meaning or provision an afterlife, any more than any other entity (universals, fundamental particles, etc.) would? Such a God seems like just a thing."
To contrast classical theism, theistic personalism does seem to have the spiritual and emotional "punch" that I would expect God to have. God-as-a-person is capable of loving us, taking and interest in our life, giving our life meaning, giving us an afterlife, and so on. While simple-God is certainly capable of all these things, it doesn't seem like simple-God would have any reason to do any of them. In fact, simple-God, doesn't seem to have any reason for preferring a world with persons in it over a dead-world without persons.
But, many classical theists who accept divine simplicity and reject that God is a person are Christians, Muslims, and Jews. They do believe that God loves us, takes an interest in our life, is something we should worship, that there is an afterlife, etc. I don't understand how all these other beliefs follow (or even could follow, given that God is not a person).
How do classical theists overcome the objection that their God is too impersonal to be of any significance to humans?