You reveal the path of life to me; in Your presence is abundant joy; in Your right hand are eternal pleasures. - Psalm 16:11
I believe Jesus was a joyful person. I don't believe He went around with a pious frown on His face. To hang with Jesus had to be fun.
As a Christian, joy should be the natural expression of your life. Your circumstances or situation doesn't control joy. Joy is the inner peace that God is in control and is working for your good.
I love that the Psalmist didn't stop with "joy." He had to add "abundant joy." Abundant joy is overflowing joy. Abundant joy is the joy that is more than enough. You can share your joy with the world because you have overflowing and never-ending joy.