"Pantheists usually believe that God, so to speak, animates the universe as you animate your body: that the universe almost is God, so that if it did not exist He would not exist either, and anything you find in the universe is a part of God.  The Christian idea is quite different.  They think God invented and made the universe--like a man making a picture or composing a tune.  A painter is not a picture, and he does not die if his picture is destroyed.  You may say, 'He's put a lot of himself into it,' but you only mean that all its beauty and interest has come out of his head.  His skill is not the picture in the same way that it is in his head, or even in his hands." Mere Christianity

Lewis points out one of the problems with pantheism.  It has to do with the claim that everything is God, or a part of God.  If this is so then cancer, slums, hunger, and all the pain in the world are parts of God.  Such an idea is certainly not appealing to the human mind.  And why is it that humans can imagine a better world than what is?  Does it not make more sense to say that what is wrong with the world is due, not to God, but to the creation itself "going astray"?  At least that is the theistic solution to the problem of evil.  According to theists evil is the result of something good God gave to part of his creation--namely--free will.

But there is a third way of viewing the relationship between God and creation which Lewis does not mention in Mere Christianity.  That is panentheism.  This is the view that all of creation exists in God.  Panentheism tries to avoid a potential problem in theism, namely the tendency to distance God from creation. (Actually theists solve this problem by pointing out, in contrast to deists, that God is providentially involved at all times and in all places, in the ongoing governance and sustenance of his creation.) Panentheism also tries to avoid the problem inherent in pantheism, of identifying God too much with creation.  Jurgen Moltmann suggests that the best analogy for this view of the relation between God and creation is not that of a father who engenders and rules over life outside himself, but that of a mother who makes room for and nourishes life within her own body.

But then one wants to ask the panentheist: Will the child in God's womb ever be brought to birth?  Will the child ever have its own existence distinct from the mother?  Will the child ever have the possibility of choosing his or her own direction in life?

Personally I find myself in greater harmony with the theistic view of creation expressed by Diogenes Allen in his book Finding Our Father.  Allen writes:

That he created ex nihilo means that once there were no realities but God.  He could have remained alone, for he lacked nothing (as the Trinity doctrine also emphasizes). . . .

He could have legitimately remained the only center, the only power around which all that was himself was related.  But he performed an ethical act, not by recognizing other realities (which he could have done only were there preexisting matter), but in the first instance by creating realities when there was nothing.  It was an act by which he limited his power; for the existence of other realities means he chooses to make and to allow for the existence of particulars which do not orbit around himself.  They are independent foci, which can rightly be objects of interest and concern to one another and to him because, as independent realities, they have legitimate worth.

As Allen points out, this creation and recognition of independent, particular realities is essential to love. If there are no particular realities distinct from God, how can God love those particulars as distinct from himself?  And how can it be said that we love him?  If we are not distinct from God, how can our love of God involve a choice? 

Clearly God has created us as distinct, particular realities who have the awesome power of choice.  God summarizes that choice in this way:

". . . I have set before you life and death, blessings and curses.  Now choose life . . ." Deuteronomy 30:19

O God, thank you for creating the universe, and me as part of the universe, distinct from yourself.  Thank you for giving me the awesome gift of free will.  Help me, by the power of your Holy Spirit this day, to choose life and blessing rather than curse and death, for the sake of your Son Jesus, in whose name I pray.  Amen.