. . . for the joy of the LORD is your strength.
If you are looking for joy, it can only be found in one place, that is, our Heavenly Father.
Joy cannot be found in earthly possessions
Joy cannot be bought with money
Joy cannot be found in a bigger fancier house
Joy cannot be found by having more friends
Think of all the things that make up the joy of the LORD, and your smile can't help but last forever. It is not possible to always be happy - but it is possible to always have the joy of the LORD.
And my soul shall be joyful in the LORD:
it shall rejoice in his salvation.