'Struggle' in the Bible

I dedicated myself to using wisdom for study and discovery of everything that is done under heaven. God uses terrible things so human beings will struggle with life.

So then I recommended enjoyment of life, because it is better on earth for a man to eat, drink, and be happy, since this will stay with him throughout his struggle all the days of his life, which God grants him on earth.

Enjoy life with the wife you love all the days of your fleeting life, which has been given to you under the sun, all your fleeting days. For that is your portion in life and in your struggle under the sun.