“Let us hear the conclusion of the whole matter: Fear God, and keep his commandments: for this is the whole duty of man. For God shall bring every work into judgment, with every secret thing, whether it be good, or whether it be evil.” - Ecclesiastes 12:13-14
Ecclesiastes is an interesting one. It goes chapter by chapter, trying to find meaning in life through process of elimination, trying education, hedonism, labor, and wealth. While some things (usually wisdom) bring about more joy in the interim, he declares that they all will lose their charm rather quickly. In the end, all joy from these will leave us before death. Solomon's last hope for fulfillment lies in the eternal and supernatural.
Solomon seems to give a glimpse into a life of "what happens if the only challenges you have are the ones you freely pick?" He had everything one could dream of and more, including an unprecedented era of peace.
Yet he struggled to pass the time. Having the equivalent of billions of [insert favorite currency here], most folks fantasize about the ideal life. We often believe all of our immediate problems go away, free to do whatever we want. Yet, at least in Solomon's case, he seemed to become incredibly fed up with these grand projects and plans of his own devise.
While I certainly wouldn't mind a fraction of that wealth myself, I do recall my college weekends. Free to spend time however I pleased, with my basic needs met and no homework looming, I spent hours playing my favorite video games. And yet, no matter how good they were, I remember how dull and boring they eventually became in only a few hours.
Which God? Yahweh, Jesus, Allah? Brahma, Amaterasu, Ahura Mazda?
The first three are the same, and the latter three are in no way related to the passage.