The biggest problem with Tillich is that he bases everything he writes on a faulty Tinitarian theology. Or, more accurately, the lack of any real Trinitarian theology. You can sum up the Trinitarian theology of Tillich (and Schleiermacher, for that matter) with the following statement:
There is an economic Trinity (how God interacts with anything which is outside of God), but there is not an immanent Trinity (the inner reality of God as three eternal persons).
If you read Tillich’s work Systematic Theology, he refers to the Trinity in strictly symbolic terms and refuses to entertain any discussion of the immanent:
Certainly, the trinitarian symbols express the divine mystery as do all symbols which state something of God. This mystery, which is the mystery of being, remains unapproachable and impenetrable; it is identical with the divinity of the divine.
He is correct in that the Trinity is a mystery. However, he is incorrect when he states that something which is a mystery is unapproachable and impenetrable. If God is unapproachable and impenetrable, how are we able to have any sort of relationship with Him? But we can have that relationship, despite the Trinity being beyond reason. Beyond reason does not mean unable to be approached via reason at all. It just means reason is not sufficient to fully express the truth of a thing.
Tillich’s conjecture is that because we cannot explain the Trinity using reason alone, we should not bother trying to talk about the inner workings of God at all and merely treat the three Divine Persons as symbols. Consider this statement he makes later on the same page:
The doctrine of the Trinity – this is our main contention – is neither irrational nor paradoxical but, rather, dialectical.
His claim is that the Trinity is not taken to be a doctrinal fact but the subject of a dialectical discussion, a Hegelian thesis/antithesis/synthesis, and examined solely from the perspective of the economic. Tillich assumes the correctness of his argument in the dialectic as the synthesis resolving the apparent tension by stating, without substantiation, that the Trinity is symbolic rather than substantive. God the Son represents something, but isn’t necessarily something. God the Holy Spirit also represents something, but isn’t necessarily something either.
The chief problem with a disregard of the immanent is that Tillich ends up describing God solely from the perspective of the economic. When God is viewed solely from our relational standpoint, everything about God is viewed from within that paradigm. The Holy Spirit is a symbol of the divinity in the Church. Jesus is a symbol of the divinity in us. They aren’t necessarily persons, and the symbols aren’t necessarily even accurate expressions of God. After all, we cannot know the inner workings of God in detail through reason alone. As long as these “persons” are at least symbolic, that is enough for Tillich.
Tillich is very much a child of his time, his upbringing, and Enlightenment thinking, concerned with the conflict which can result from not being able to give definitive, unassailable explanations of the immanent Trinity, and desperately seeking to resolve the tension of that conflict through the use of Hegelian dialectic. He takes the existence of disagreement to be a failing in trying to comment on the immanent Trinity, rather than a failing on the part of humans who would try to explain a divine mystery by using human reason divorced from faith. It’s a very Enlightenment, a very “reason alone”, way of thinking. Hardly a better example exists for this than his statement about the Blessed Mother that he makes only ten or so pages after beginning his discussion of the Trinity:
The symbolic power of the image of the Holy Virgin from the fifth century after Christ up to our own time raises a question for Protestantism, which has radically removed this symbol in the struggle of the Reformation against all human mediators between God and man.
Again we see the reduction of a person to the merely symbolic. As he does with the persons of the Trinity, Tillich views the person of the Blessed Mother less as an actual person and more as a symbolic representation of some sublime meaning. He devotes multiple pages to this topic during what is supposed to be his explanation of Trinitarian theology, which I find rather amusing. Objective reality is not really relevant to him; subjective relationship (the symbolic meaning a person can attach to a thing) is what matters.
To see where Tillich is coming from, it helps to be familiar with Schleiermacher. Schleiermacher uses only the last dozen or so pages in the sixth and final volume of his work The Christian Faith to talk about the Trinity. The Christian Faith was published about 55 years before Tillich was born. The ideas in The Christian Faith about the Trinity, that we can talk about the economic Trinity but must “call a halt” at any discussion of the immanent Trinity, are what laid the groundwork for Tillich. He is merely taking the thoughts of Schleiermacher and bringing them to their logical conclusion 120 or so years later - the Trinity is something purely symbolic and can be approached from the perspective of the economic, but is not really an immanent reality. Or, to put it quite bluntly, God’s objective reality is defined by our subjective view of Him.
And that narcissistic statement is, honestly, pretty much what liberal Protestant theology is all about.
