These things I have spoken to you, that in Me you may have peace. In the wold you will have tribulations; but be of good cheer (have joy!), I have overcome the world'. Jesus in John 16:33
Okay...consider this...the possibility that many believers don't experience joy simply because they are self-centered.
Regardless of our situation, there will always be others around us in need. By focusing on our own problems, we only make them worse in our own minds. The reality is this: we DO have reason to rejoice no matter what the circumstances...not in ourselves, but in GOD!
If our true security is in Jesus, we would reach out to someone else in our times of trouble knowing that self-pity can be turned into deep joy by the simple act of the will towards someone else. It is a reality that turning our thoughts, acts and will towards someone else fills us with unexplained joy..."And the Lord restored Job's losses when he prayed for his friends." Job 42:10.
No matter what our trials are, no matter what our situation is, God calls us to give of ourselves to others. In this giving of our time, love and acts of kindness, God replenishes us with His joy. It works. Try it.
"Lord, please fill me with a desire to give of myself today. You intimately know my struggles and circumstances; help me to rise above them and give of myself to a needy person today. Provide me this opportunity and bless me with Your joy. Amen."