Some Metaphysical Background
In this work, I am seeking to answer the question Why did God create the world? I intend to show what end (purpose or goal) God had in mind that motivated him to bring the world into being.
The End for Which God Created the World, by Jonathan Edwards (Author), Jason Dollar (Editor)
Edwards admits that trying to tackle this question – trying to understand God’s mind – is a daunting task, certainly confusing. Being a Biblically well-grounded Reformed theologian, he does have some help via Scripture, of course.
Edwards begins by making the distinction of a person’s chief end and his ultimate end when one does something for a purpose. To get the easy one out of the way: an ultimate end is sought for the sake of itself and nothing further; it is sought for its own innate and intrinsic value. There may be subordinate ends that are necessary to achieve in order to be able to achieve the ultimate end, but the ultimate end is the final objective in view.
A man wants to grow crops in his yard to feed his family. Feeding his family is the ultimate end, yet it is not difficult to consider various subordinate ends necessary to achieve this ultimate end: buy appropriate tools, secure seed, ensure water and good soil, protect the crop from predators, etc.
As for a chief end, it can be also called the highest end. It is a matter of quality. To understand this, consider the reality that a man can have two or more ultimate ends – which one is the chief end, the one with the highest value or quality?
A man has an ultimate end to look at the stars through a telescope; he also has an ultimate end to secure a bride. These are independent of each other, not mutually exclusive; each can be achieved without disrupting the possibility of achieving the other. Per Edwards, the man will consider finding a bride to be his chief end – the one of higher quality, the one more important to his being.
A subordinate end can be more valuable than an ultimate end with which it is not associated. We can see this even in the example of the telescope and the bride. It may be more important to the man to take the step of meeting friends who can introduce him to eligible young ladies than it is to secure the ultimate end of looking at the stars through a telescope.
However, a subordinate end cannot be more valuable than the ultimate end to which it is subordinate. Finding friends who can introduce the man to eligible young ladies is not more valuable than finding a suitable bride. The subordinate value has zero value if not for the ultimate end from which it is derived.
We can even see the case of this in economics: a good is not priced based on the intermediate goods required to produce it; the intermediate goods are, instead, priced based on the value to be realized by the ultimate (finished) good.
An ultimate end and an end that is subordinate to it might have equal value. For example, if the only way to achieve the ultimate end is through one specific subordinate end, the subordinate end is as valuable as the ultimate end.
Ultimate ends, subordinate ends, chief ends. But there is still to be considered a supreme end. There is a supreme end if a being has one end in mind for all of the other ends he is pursing.
This seems to be how God approaches his works. He has a supreme end in mind for all he does, and everything he does is aiming toward the one supreme end.
So, what of God and ultimate ends? And what might these say about His supreme end, the purpose for which He created the world? How might an examination of this help us to understand God’s motivation for creating the world?
What we find in God is that He has many ultimate ends – things He values for their own sake. Yet He also seems to have one ultimate, or supreme, end in mind. In this case, God had some particular good thing in mind that inclined Him to create the world. Once created, other ends came in to view – call these consequential, or dependent, ultimate ends.
Take, for example, justice. God loves justice for justice’s sake, but from this we cannot conclude that the reason He created the world was to achieve or demonstrate justice. The necessity of justice came out of His creating the world, but wasn’t the purpose or end of creating.
Or what of His faithfulness. Here again, we see an ultimate end for God, but we cannot consider that He created merely to have an opportunity to show His faithfulness. After all, it was only after He created that He had reasons to bound Himself to His promises.
Conclusion
There is some original ultimate end alone that motivated God to create the world – His supreme end. From this end, He was able to obtain other consequential and dependent ends. This original ultimate (supreme) end must be the same for all of His other works – if any of His works had different ultimate ends, then, inherently, these were in service to some higher, common, end.
In this, we may take a clue from His works of providence: the ultimate end for these must be the same as His ultimate end for creation. God’s providential work as a whole is the same as the general use He has for the world He created.
In fact, when we analyze God’s works of providence, we should be able to conclude the end for which he made the world.

I think it's very simple: God wants a Family that loves Him. Also He likes a challenge .. a difficult game to play with a true chess-master as his opponent! Why does anyone have a dog or a cat? And He wants a beautiful Home to live in with His family. Just my humble thoughts. One time his mother and brothers came to see him, but he says: whoever does what I say, the will of God is my mother and brother and sister. And the judgment in Matthew 25 is based upon how people have treated his brothers and sisters.
I suspect that the answer is in John 17, which is either orthodox theosis or heterodox one-with-the-oneness.