“I told you these things so my joy would be in you all— and so your joy would be filled.” —Jesus,
“These things” refers to the things Jesus had just told his students in his Passion Discourse—how he’s the vine and they’re the branches, how obeying his commands results in getting what we ask for. Jesus told them, and us, this “so your joy would be filled.” The KJV, and various worship songs, have it “that your joy might be full.” But not everyone understands just what Jesus means by describing joy as full. Doesn’t that mean we’d be full of joy?
No. Pliró’o is a verb, not a adjective; it’s something that has been done to joy, not something that joy is. Jesus is not saying his followers will be full of joy, but that his followers will have joy that has been filled. Pliró’o means “fill,” and usually “fill until full”—not partially, but entirely. The joy is filled to the full.
With what? Well, that’s the tricky idea. Joy is not a material object. It’s an emotion, and a concept. It’s not something you can literally fill; it’s not a container with a maximum capacity. Full, in this case, means that it’s full of a certain quality that joy ought be full of. And we can deduce what this quality is by considering the opposite of a full joy: An empty joy.
Joy is a synonym for happiness, despite what some Christians teach. Jesus wants us to be happy. But Jesus doesn’t want us to have an empty happiness—a happiness that’s based on nothing. Perhaps you’ve encountered the “happy Christian”: These would be the people who want you to believe that, thanks to Jesus, their lives are great, their relationship with God is solid, their faith is strong, and everything is just peachy. And to prove it, they’re gonna bubble over with all the enthusiasm of a used car salesman… and weird out everyone around them. Because anyone who looks into their eyes will notice how, from the way their eyes don’t crinkle up, that the big smile frozen in place is a big fake smile, and that inside, they’re in agony. Especially if they’re the sort that doesn’t drop the act once they get home.
That would be an empty happiness, based on nothing but a veneer of well-being. Or based on the popular belief that, since joy is a fruit of the Spirit and Christians ought to exhibit it, perhaps we ought to live like we have it already—perhaps we ought to claim that joy for ourselves and our lives, and order it into existence—and then we actually will have it. But this is stupid. Joy doesn’t exist on its own: It requires something to be joyful about. It requires something substantial—and preferably something real instead of imaginary. It requires something that one ought to be happy about. It requires Jesus.
The source of the Christian’s joy ought to be our relationship with Christ Jesus. It’s okay to take joy in our work, in our family, in our friendships, in our hobbies, in entertainment, and so forth. But the source of those joys must likewise be in our relationship with Jesus. You ought not enjoy your job unless you’re doing it as Jesus would have you do it. You ought not enjoy your family unless you’re caring for them as God cares for you. You ought not enjoy your hobbies and entertainment if they tempt you to sin (I should say when they tempt you to sin, for they will; everything in this world does) but you ought to be able to enjoy them just fine when they don’t, and when you’re enjoying them in a healthy way.
The reason for this is that Jesus is the only permanent thing in our lives. Relationships with other people begin and end. Jobs come and go. Entertainment is definitely temporary. And when our joy is rooted in those things, our joy is also temporary. It‘s fleeting. I remember friends from high school, whom I thought were close friends, and when I tried to catch up with them some years later, I discovered the only things we had in common were politics, and songs and TV shows from the popular culture. Nothing permanent among them. Jesus would have been permanent, but we didn’t share him in common either. Jesus would have made us brothers. Instead, we were estranged.
Jesus wants us to be joyful, but our joy must be based on something meaningful. This world doesn’t provide us with much of that. Lots of people are looking for meaning, because they want something to be joyful about. They figure once they find it, they’ll have joy. They’re regularly disappointed, because once they find something that ought to give their lives meaning, it actually doesn’t, and they have no more joy than they did before. Or, like Christians, they don’t let it give their lives meaning: They assume that because they possess truth, that’s enough; they needn’t shape their lives around it. And after a while, their discontent starts them searching again. Hopefully this time around they’ll actually meet Jesus, but we’ll see.
Jesus doesn’t want our joy to be empty. He wants it to be lasting. He wants it to stand up despite the whirlwind of chaos around us. He wants it to stand up to testing and opposition and accusation and persecution. He wants it to back up our love, peace, patience, kindness, goodness, and fidelity; and produce faith, hope, and love. He wants it to be full, or “complete,” as the GNB, NRSV, and NIV put it. Can it be? Only when we make Jesus our joy.