I'm not now, nor have I ever been, a joyful person. I have known moments of pure joy that broke on me so suddenly and serendipitously that they stand out in my memory like ship's masts above a fog bank. But I also know that I have found joy more often when I have put myself on God's path, not my own, and especially when I have joined with faithful hearts who were also seeking that path.
I suspect that Paul wasn't by nature a joyful man either. By this point in his career he had suffered greatly, and he awaited the dread culmination of his suffering. But he refused to yield to the darkness that loomed around him. He found great encouragement in the lives and perseverance of his friends, his companions in the journey, and even if he never sees them again, he wants them to carry on in his absence. So he leaves them (and us) with all these gemstones of encouragement:
our citizenship is in heaven
my brothers and sisters...my joy and crown
He will transform our... humiliation...into glory
stand firm in the Lord...my beloved
Rejoice in the Lord always; again I will say, Rejoice!
The Lord is near
At times, too, I have been an anxious person, to a degree that I could not shake loose for long fretful stretches of time. Paul's enjoinder to not worry about anything (but pray) is the best advice anyone could give or get. I need to take that Rx, daily.
And then that wonderful benediction. May the peace of God that passes all understanding keep our hearts and minds in Christ Jesus.