Following on from the near nonsense about Tillich from J. I. Packer, there is a much better commentary from a blogger regarding Tillich and comparison with John Hick's scheme.
I would emphasise the difference further than he does, in that Hick still has a kind of metaphysical theism whereas the existential language alters the metaphor in Tillich. But Tillich has a hermeneutic circle and you have to be within his systematic language to provide those Christian answers via the existential language that is the basis of questions from the outside or inside.
Tillich is not then like Hick; Hick is pluralistic regarding Christology and he is universalist (and unitarian - small us) regarding God or the transcendent that he renames the Real. Indeed Hick's Christology is purely subjective (and is so because his Real remains objective) and his Real is beyond specific descriptions (to avoid starting a new religion).
What Hick tries to do is have main religions as salvation schemes for which he makes no particular comparative judgment, and then he does not define the Real. But he has defined it so far, and far enough to suggest an entity however spiritual that Buddhists would not accept or find superfluous. It also implies the Trinity is but a local expression of a greater whole, and that would not be accepted by many Christians.
Hick, however, does to Buddhism and to Christianity what they do not accept - Buddhism does not have a Real that is equal to that of Christianity, for example, or anywhere near, and Christianity does not accept that the Trinity is but a local expression of a greater Real. In the end, religious expressions are their own, and Hick is adding another layer.
That other layer is simply Unitarian. The Unitarian view of God tends to be limited in statement, and that all expressions are but poetic. Also, after James Martineau, one's view of Christ is one's own. He had it that we today (then, now) are not looking for a Messiah and they (first century) were, and that therefore their biblical expression is just one kind of transient expression towards the actual vastness of religion, the theism to which it points. John Hick is saying pretty much the same, whilst seeing salvation schemes as packages (whereas Martineau makes a further move to what is important: against that, though, Martineau's liturgy was conserving to maintain religious expression and avoided the interfaith implications of his method).
Hick may be a closet Unitarian, in that it has been pretty much done before and long ago, but Tillich clearly maintained a Christian system. And this is why Packer is wrong.
A view from the gallery - http://changingattitude.org.uk/wp-content/uploads/2017/02/GS-A-View-From-the-Gallery-75x42.jpg 75w" sizes="(max-width: 299px) 100vw, 299px" /> When I was a ...