Read James 1:1-4.
"Consider it pure joy, my brothers...." NIV
James, the brother of Jesus, identifies himself as a servant of God. In the Greek that is a slave or bondservant. A much stronger word than our word "servant" implies. And he is a servant of "the Lord" Jesus Christ. Not just Jesus Christ. James is acknowledging the deity and sovereignty of Jesus Christ. Lordship means that Christ is over all James does and all he is. James is surrendered completely to Christ's leading. (He wasn't at first, but he certainly is now.)
The Dispersion is referring to the scattering of the Jewish believers. This Dispersion happened after Christ's death and resurrection when the Jewish Christians were scattered out among the Gentiles. As the head of the Jewish Christians in Jerusalem, James wanted to encourage and instruct his people who were living in foreign lands among foreign customs and beliefs.
James begins with joy in trials. Not happiness in trials -- we are never told we have to be happy about difficulties. Happiness is an emotion associated with circumstances. Joy is a choice made deep within our spirit. That's really the only way to have joy in trials -- seeing them as a passing moment that will not rob me of the hope God has given me.
However, trials do test our faith. They push us to the point of once again deciding, do I believe God is who He says He is and will do what He says He will do. (Beth Moore's Believing God) Can I trust in His promises to always be with me through everything I face; to never give me more than I can handle; to hear my cries; to hold me in my distress?
I love that word, "steadfastness." The NAS says it even better, "endurance." And the KJV says, "patience." All these words infer longevity, hope, and commitment. The more our faith is tested and we maintain the integrity of our beliefs through it, the stronger is our commitment to continue through whatever the enemy throws at us. That's why we have joy in trials. They may not be any fun now, but if I handle them with the grace and tenacity that my Lord gives me, I will come out the other side a stronger servant for Him -- one that will go the long haul. That's the person that God wants to use for His mission to the people of this world. He needs the trial endurers that possess an unwavering faith so that when the storms come, they will stand.
Oh my Lord, I will joy in my trials as long as it makes me a more faithful servant of You.