I wonder how many Christians lead joyless lives because they wallow in the weight of their past sins. “If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness” (1 John 1:9). Repent, confess, ask for forgiveness (early and often), and pray for joy. Therefore, we are to consider the trials of this life pure joy, more than happiness, for God is at work in us for our good and his glory.
The term joy is often misunderstood by modern Christians because of the way it is defined and used in our culture today. Joy is often considered a synonym for happiness, which in modern use is understood as more sentimental than substantive.