'Worthwhile' in the Bible

The only worthwhile thing for a human being is to eat, drink, and enjoy life's goodness that he finds in what he accomplishes. This, I observed, is also from the hand of God himself,

I have concluded that the only worthwhile thing for them is to take pleasure in doing good in life;

I concluded that it is worthwhile for people to find joy in their accomplishments, because that is their inheritance, since who can see what will exist after them?

Therefore, this is what the LORD says: "If you repent, I'll take you back and you will stand before me. If you speak what is worthwhile, instead of what is worthless, then you will be my spokesman. People will turn to you, but you aren't to turn to them.