When philosophers talk about ‘god’ are they referring to the God, or instead a human projection of a no-God? When atheists talk about ‘god’ are they referring to the God, or instead a socio-phenomenal construct of god that they have inherited tacitly from the cultures (largely Western per the assumption of this post) they have grown up in? I would contend that philosophers and atheists who claim to have “discovered” a concept or notion of God, and then utilize that discovery to talk about God in universal and totalizing ways are not in the end talking about, at least, the Christian God. The Christian God is known only through His Self-revelation, there is no other way to come to know the Christian God who is Triune; the Christian God who is Father, Son, and Holy Spirit — this is the stuff of revelation.
But this reality in and of itself does not mitigate the fact that all of humanity in one way or another engages in theological reflection; it is just that Christians are the only ones to do so with reference to the true and living God. It is good to know this though, isn’t it? That all of humanity does theology; that all of humanity because they are created in the image of God, and recreated as images of the image of God in Christ have the propensity to want to live into the reality for which they were created. It is just that without the Spirit people are left to their own devices, which means they are trapped within themselves to only think from themselves, and thus project out of themselves a conception of god that sounds and looks exceedingly like humanity (just elevated). Karl Barth says it this way:
Theology is one among those human undertakings traditionally described as “sciences.” Not only the natural sciences are “sciences.” Humanistic sciences also seek to apprehend a specific object and its environment in the manner directed by the phenomenon itself; they seek to understand it on its own terms and to speak of it along with all the implications of its existence. The word “theology” seems to signify a special science, a very special science, whose task is to apprehend, understand, and speak of “God.”
But many things can be meant by the word “God.” For this reason, there are many kinds of theologies. There is no man who does not have his own god or gods as the object of his highest desire and trust, or as the basis of his deepest loyalty and commitment. There is no one who is not to this extent also a theologian. There is, moreover, no religion, no philosophy, no world view that is not dedicated to some such divinity. Every world view, even that disclosed in the Swiss and American national anthems, presupposes a divinity interpreted in one way or another and worshiped to some degree, whether wholeheartedly or superficially. There is no philosophy that is not to some extent also theology. Not only does this fact apply to philosophers who desire to affirm — or who, at least, are ready to admit— that divinity, in a positive sense, is the essence of truth and power of some kind of highest principle; but the same truth is valid even for thinkers denying such a divinity, for such a denial would in practice merely consist in transferring an identical dignity and function to another object. Such an alternative object might be “nature,” creativity, or an unconscious and amorphous will to life. It might also be “reason,” progress, or even a redeeming nothingness into which man would be destined to disappear. Even such apparently “godless” theologies are theologies.
I like to remember this when I am conversing with people who claim to be atheists, agnostics, or just plain ole’ garden variety pagans. Because we were created to worship it is a fundamental aspect of human nature to want to worship. Of course given the reality of what Luther and others called homo in se incurvatus, or humanity incurved upon itself, again humans left to themselves will theologize about themselves. Sure they will call their god something or someone else other than themselves, they might even call their god, God, but unless they have the Spirit of God they have no hope or possibility for speaking or referring to the true and the living Triune God.
Next time you are talking to a person who claims to not be religious, or who claims to be an atheist or agnostic just remind them that one way or the other they do theology every day. It might not be the best theology, but it is indeed theology; there is no escaping this reality, it is a fact of human being.
 Karl Barth, Evangelical Theology: An Introduction, 3-4.