When we are asking a ‘why’ to God, we should first ask why should God after all?
Whether we like it, believe it, accept it, or not, he wants to exist , he exists.
Biblical understanding is that, God is Spirit, God is Love.
Both seemed to be quite an abstract ones. We are concrete in appearance , but spirit in essence.
Concrete things are transient. where as Spirits are not. Again i considered from the catholic point of view. We may be able to kill the body, but cannot kill the soul. Nor can we create a single soul. And without soul body cannot exist. Soul can exist without the body.
There is a clue.
Now the eternal God created human out of love. Like a painter who contemplated about the painting in his mind, God contemplated about his creation in his mind from eternity.
Like the painting came into existence, the human beings, along with the wonderful creation came into existence.
Considering the question, why God created the creation , it is again LOVE
God is Love. Love is not God. Deeply mystical element. The concept of love.
Unless and until one comprehend what is Love, one cannot begin to know what is the Reason for Creation. One should be mindful, that one is trying to read the mind of God.
The beloved disciple , John lingered on and tried to comprehend. he reached somewhere. that is , GOD IS LOVE. God is Spirit.
So it looks like it is the coexistence God the Spirit, with the created spirits, or the souls in the crucible of love. The aberration , which was again predestined by God, the fall in the Garden of Eden did only magnify the theme of LOVE by the coming of the Redeemer, the Messiah.
Love can exist only if there is something or someone to be loved. God needed us.!!! !!! !!!
Once we grasp the theme of love, necessarily, the opposite comes to our mind. That is hatred.
Thus with out the creation to be loved, God is prevented from loving anything, anyone.
So God, in turn has to exist side by side. Or in unity. If the love vanish simultaneously, God vanish. By definition, God cannot vanish. Thus love need to be perpetuated.
Surely, the creation becomes the necessary for God to be present live in its purest sense.
Anything with imperfection cannot be loved without reservation. The created spirits are like God, but not God. They can be loved in the purest sense.