Mother Teresa said;

“The password of the early Christians was joy, so let us still serve the Lord with joy. Joy is love, joy is prayer, joy is strength. God loves a person who gives joyfully, and if you give joyfully you always give more. A joyful heart is the result of a heart burning with love. Works of love are always works of joy. We don’t need to look for happiness: if we have love for others we’ll be given it. It is the gift of God.”