'Rejoice' in the Bible

There is no end to all the people nor to the past generations, yet future generations will not rejoice in him. This also is profitless and like chasing the wind.

So, if a man lives many years, let him rejoice in them all, but let him remember that the days of darkness will be many -- all that is about to come is obscure.

Rejoice, young man, while you are young, and let your heart cheer you in the days of your youth. Follow the impulses of your heart and the desires of your eyes, but know that God will judge your motives and actions.