Paul Tillich (1886 – 1965) was a famous German Lutheran Theologian. I was introduced to Tillich through Michael Horton's A Christian Faith: A Systematic Theology for Pilgrims on the Way.  Horton made great use of Tillich's dialetic between "overcoming estrangement and meeting a stranger" to show the tension between deism and pantheism (See Tillich's Theology of Culture for more details.) 

Pantheism isn't what most people think it is, and those who are Pantheists do not describe themselves in the way that non-Pantheists describe Pantheism. There are some basic theological problems that Pantheism helps overcome, such as the problem of mathematical laws; are these laws created or eternally existing besides God? If they exist besides God, then they are uncreated and immaterial and that makes God subjected to the eternal Mathematical laws, which is a huge problem. There's also the idea of a Creator, and if something could exist without the sustaining power of the Creator, then it wouldn't have the feeling of absolute dependance (Schleiermacher) on God, but would become its own God. 

I'm reading an amazing history book by Paul Tillich, Perspectives on 19th & 20th Century Protestant Theology (edited by Carl E. Braaten); It was mentioned by the editor of Barth's Protestant Theology of the Nineteenth Century as a similar book with more recent discussion. However, I see Tillich as providing a more modern commentary over the same survey because Tillich doesn't address more than Barth had, but yet he is an excellent second opinion. The evaluation of Tillich by Carl E. Braaten (the editor) was that Tillich was never received like Karl Barth because Tillich didn't provide the fine print that was interwoven through Barth's Church Dogmatics. As my friend Ben Merritt has said, the fine print is often the most excellent part(h) of Barth. (I'm still bitter that Ben was first to pronounce 'Barthian' correctly.) I admit that I overpaid for a used and old copy of the Church Dogmatics: Vol II. The Doctrine of God and the most annoying and interesting part of my smelly old book was the previous owner wrote "cf. Tillich!" on almost every page. 

So in Perspectives on 19th & 20th Century Protestant Theology, Paul Tillich defends(?) himself against accusations of Pantheism with most most winsome polemic for Pantheism I've encountered so far. I know most Christians have been taught to recoil at the word 'Pantheism' as if it were some Hindu-Buddhist babel but like I said, there may be a way to salvage some of it for good! For instance, the problem of Platonic forms, as solved by Augustine, was to say that those forms that we only experience of particulars (like the form of a horse opposed to any particular horse we actually experience in ride) was to say that those forms are actually dervied from the Logos of God (i.e. God himself is the generation of all Natural Laws), and that Makes sense based on John 1:1ff. So I encountered the following extended section in Tillich's book I'm reading, and wanted to share it with you: 

Spinoza, of course, was modified. It was not the geometical Spinoza. Those who know a little about Spinoza know that he called his main work Ethics,  but ethics more geometrico, ethics written by the use of the geometrical method. As a title this is in itself of greatest interest. He tried to use the all-powerful mathematical methods in discussing such subjects as metaphysics, ethics and politics. All of this is presented in a way which makes the world into a geometrically describable world. This was a very static concept of the world and of the divine ground of the world. He called this "the substance." In any case, this idea was founded on the principle of identity over against the principle of detachment and depths of everything. He is not everything, as this much abused term "pantheism" says. Nobody has ever said that. It is absolute nonsense to say such a thing. It is better to avoid the term itself, but if it means anything at all, it means that the power of the divine is present in everything, that he is the ground and unity of everything, not that he is the sum of all particulars. I do not know any philosopher in the whole history of philosophy who has ever said that. Therefore the word "pantheism," which you can translate as "God is everything," is down-right misleading. I would wish that those who accuse Luther or myself of pantheism would define the term before using it. And, of course, Nicholas of Cusa, Schelling, Hegel and Nietzsche, and many others are accused of pantheism. As if everybody who is not a supernaturalistic deist or a theist--and theism as the term is used in America today is nothing else than a supernaturalistic form of deism--is a pantheist. Whenever some people hear about the principle of identity, they say this is pantheism, which supposedly holds that God is this desk.

Now, of course, Luther would say that God is nearer to everything than it is to itself. He would say this even about the desk. You cannot deny that God is the creative ground of the desk, but to say that God is the combination of all desks and in addition all pens and men--this is absolute nonsense. The principle of identity means that God is the creative ground of everything. What I dislike is the easy way in which these phrases are used: theism is so wonderful and pantheism so horrible. This makes the understanding of the whole of history of theology impossible.

page 94-95, Paul Tillich, Perspectives on 19th & 20th Century Protestant Theology, edited and with an introduction by Carl E. Braaten.

Thought provoking? I think so!