"This joy I have, the world didn't give it and the world can't take it away." This is a common phrase heard frequently in the Christian community, probably because it's true. The source of our joy cannot come from worldly things. The world isn't reliable. The world isn't consistent. Our joy cannot depend on something so erratic. Choosing God as the source of your joy means no matter what troubles come your way, you will always have joy because your source is reliable and consistent. 
 
Read Romans 15:13
When lighting this candle, think of where you see your current source of joy and how you can depend more on God for this.