Here is what I've thought through so far. Joy is more than just feeling happy. I found this article by John MacArthur that contained this definition of joy:
"Biblical joy consists of the deep and abiding confidence that all is well regardless of circumstance and difficulty. It is something very different from worldly happiness. Biblical joy is always related to God and belongs only to those in Christ. It is the permanent possession of every believer--not a whimsical delight that comes and goes as chance offers it opportunity.
A good definition of joy is this: it's the flag that flies on the castle of the heart when the King is in residence. Only Christians can know true and lasting joy.
A Christian's joy is a gift from God to those who believe the gospel, being produced in them by the Holy Spirit as they receive and obey the Word, being mixed with trials with a hope set on future glory. "
Joy is a gift and it permeates the lives of those whose hearts belong to Jesus. That is why when we look at the seemingly insignificant things around us, we see evidence of His blessings, and we are filled with joy.
I understand that kind of joy, but it is the "confidence that all is well regardless of circumstance or difficulty" kind of joy that is a bit harder to fathom. It is the kind of joy Paul experienced even during times of terrible persecution. It is, much to my amazement, the kind of joy I have experienced in my own life.
I walked through a valley of suffering that I thought I would never survive. My life was not in danger, but life as I knew it had changed, and I didn't think there would ever be joy again. I pleaded with the Lord to make it different - to make it better. Heaven was silent. I became silent. I was disappointed and angry.
At some point we are faced with the reality that we have a choice to make. Mine was to remain angry at God, hoping I could somehow coerce Him into doing things my way, or surrendering to His will. I really wasn't sure what His will was, I only knew that I could not walk away from Him. I had nowhere else to go. I chose to believe that He was all that He said He was - loving, faithful, merciful, just - that He had a plan that was for my ultimate good.
When I chose trust, He gave me His peace. It came slowly, quietly, unexpectedly. I just realized one day that it was there. And then came joy - even laughter.
The circumstances did not change. I did. It was nothing, however, that I did on my own. It was a gift from the hand of a Father who loves me perfectly and has promised to work all things together for my good. Left to my own devices I would still be buried under a load of anger and bitterness. It is His Spirit working in us that makes the difference.
I come to Him with empty hands and He gives me gifts whose worth can never be measured. Amazing grace. Amazing love. Amazing joy.