Being joyful is a choice that we make. Our attitude is our choice.
"Count it all joy..." "Rejoice in the Lord always, and again I say rejoice."
"Consider it pure joy, my brothers and sisters,[a] whenever you face trials of many kinds, 3 because you know that the testing of your faith produces perseverance. 4 Let perseverance finish its work so that you may be mature and complete, not lacking anything. " James 1:2-4
No matter what the circumstance we choose our attitudes. In our human condition it is all to easy to choose to be grumpy or angry or envious. It takes more effort and more awareness, and more care to choose to be joyful. In truth, being joyful in all circumstance might not be appropriate. For example, if we visit a widow who has just lost her husband, being joyful might be insensitive to her grief.
What does true joy look like? It is so easy to get it confused with happiness. Does being joyful mean that we are to be happy all the time?
Part of joy is putting away the selfish anger that so readily available. Also, putting aside our selfish desires. Much of our anger comes from our unrealistic expectations.
Being joyful is about putting aside our own selfish interests