When Christians think of God - we should do so from a dual perspective that he is both out-there - external to us; and also within us - inside our awareness.
(We are Sons and Daughters of God: that is how God is IN us.)
However, the externality of God has been much more greatly emphasized in Christianity, to the point that it has been seen as a religion of 'some God up-there in Heaven, telling us what to do' - because the externality of God has in times and places been used to make a religion of rules and obedience only.
By contrast, 'Eastern' religions such as Hinduism and Buddhism often have a much stronger emphasis on a god-within - that we are ourselves gods, and that the way to contact the gods is to look within - by meditation and spiritual disciplines.
In the nineteen fifties and sixties, the spiritualism of the time made much of this difference between Western Christianity with its God out-there, and Eastern mystical traditions which look within.
Reading Joseph Campbell, who was raised as a devout Roman Catholic in the Irish tradition of the early 20th century, he makes this contrast repeatedly and persistently in explaining the difference between West and East - and he personally had rejected the externalizing 'objective' concept of Christianity and embraced a 'subjective' inner directed Eastern spirituality.
For people like Campbell (brought-up Christian), Eastern spirituality was about a fresh and exciting emphasis on personal growth, creativity, aesthetic appreciation, embrace of modern science - it was all positive, expanding, joyful.
But a god who is merely inner is inadequate, just as a God who is outer is inadequate - very obviously so.
A god who is merely inner is just our-selves - and such a religion is (or soon becomes) a disguised form of self-indulgence; while a God who is merely outer is just a tyrant, running a political system (it would perhaps seem more noble to defy such a purely external god than to worship him).
Joseph Campbell had had a solid grounding in Christianity as a child, therefore when he embraced an inner-orientated Eastern Mysticism, in reality he was bringing the effect of that up-bringing with him into the East, and was living a hybrid.
Likewise, the actuality of Eastern religions is that there is a very large element of the external gods about them; gods who set rules and expect obedience - and this objectivity may be very heavily emphasised in the lives of ordinary adherents.
But it is a damning indictment of the Christianity Campbell grew-up with that it had drifted into a near-exclusive emphasis on the externality of God. That style of Christianity emphasized obedience to rules to the extent of crushing the qualities of personal growth, creativity, aesthetic appreciation, embrace of modern science which Campbell and others like him actively needed.
Yet God must be out-with us in order that He explains anything; in order to structure our lives and to make us a community of believers, in order that life has purpose and meaning.
And God must be carried with-in us in order that the meaning of life may be experienced as alive; that we have a personal destiny as creative, imaginative, exploring individuals.
So to find God we can look outside; and we also can look inside.
God is wherever we are because he can always be contacted in prayer, and God is wherever we are because we always carry him around.
We can pray to our Father in Heaven, and we can do this in a group and share the experience; and we also can meditate, attune with our inmost being in solitude - and we will find God there too.
How is this achieved? - mostly through knowing God in a relationship - as our Heavenly Father. God is out-with me because he is not me - he is another person. And God is with-in me because I am my Father's Son, and my Father is therefore intrinsic: part of my make-up.
To use a biological metaphor - I am unique, in being a one-off combination of heredity and experience and specific circumstances; but I also have genes which I got from my parents, and which I share with all other humans - men and women.
Therefore, I am both generic and distinctive.
And I must be both to be Human.
So Christians should take care not to neglect God within us - actual Christian doctrine and life should never make it possible to draw the outer versus inner contrast that Campbell experienced and taught.