We were created to serve. Therefore, when we serve we are fulfilled, and fulfilled people are happy people! Also, how on earth do we show Jesus to our world without serving. How do you present a God who is the ultimate servant to the world without serving in some way?
So, my dear brothers and sisters, be strong and immovable. Always work enthusiastically for the Lord, for you know that nothing you do for the Lord is ever useless. -1 Corinthians 15:58