When Paul Tillich introduced the concept of the “God beyond
God,” a famous phrase found in his two volume Systematic Theology, there was
legitimate excitement again about the prospects of a Christian philosophy
alongside the work already being done by such heavyweights as Karl Barth. This
phrase referred to the idea that above and beyond the anthropomorphic
representations of the god who finds his way into the narratives of Judeo-Christian
scripture, there was a god-principle that exists as the ground of all being.
This god was the formless, timeless reality, to quote Thomas Aquinas
“whose essence was existence itself.” In this sense, any God formed below this
philosophically rooted god was inferior in nature and scope. He was subject to
passions and moral deficiencies, a point borne out in scripture where Yahweh
regularly shows such emotions as anger, sorrow, and even love. 
For Tillich, however, this lower stratum of godhood was an
essential concept as well, primarily because like Barth, he believed that the
God beyond God was radically transcendent in a way that made human communion
impossible with such a reality. The intermediary of “God in the flesh” was
consummated then in the person of Jesus Christ. While the God of the Hebrew bible
was certainly similar in form and function to the Greek gods or any other god,
the prospect of Jesus made possible God in the fullness of time (kairos) through the fullness of man. If
humanity had any chance of penetrating God, it was through the formal witness of Christ.
The concept, however innovative, in as far as Christianity was
making use of philosophy, was hardly new to religious reflection. Hinduism had
for thousands of years, for example in the laws of Manu and the Vedas Samhitas,
made the distinction between Brahma, an anthropomorphic god with four arms and
four heads, posturing as the head of the trideva godhead in Hinduism against the life force
of all existence known as Brahman. In this latter concept, Brahman is the existential unity
of all reality and the efficient and final cause of all that is and all that exists,
even Brahma himself. Brahman subsumed into itself Brahma in the same way
Tillich asserted that God as the ground of being subsumed into himself the God
of the bible. Perhaps most notable is that scholars believe the concept of
Brahman developed about a thousand years earlier than the anthropomorphic
stories of Brahma. In Christianity, because the concept of God as the reality
of all being appears outside the more practical interventionist language of an
anthropomorphic God in the bible, the former is often seen as a late, if not uninspired,
addition to the tradition. This is one reason why you won’t find much teaching
on it without a heavy capitulation to the anthropomorphic tradition. Unlike
Hinduism where philosophical schools flourished outside the bhakti worship
traditions of India, Christianity’s philosophical tradition was often remanded
to the university and left out of the church. Today in India, you may be lucky to
find a handful of temples to Brahma despite his prominence in the Hindu
pantheon. Given these differences in development, it is interesting to note
that the latter tradition gets less attention in the practical and day-to-day
experience of the two religions.
