In Jesus’ prayer to his Father in John 17, he makes a connection between the things he says and the joy of those who trust him.
“…these things I speak in the world, that they may have my joy fulfilled in themselves.” (Jn. 17:13)
Strikingly, he prays that believers will experience his own joy. Jesus’ desire is that his followers have Jesus-sized joy, and his words are instrumental to their own experience of his joy. Whether or not the ‘these things’ Jesus are referring to is the whole Farewell Discourse (Jn. 14-17) or this prayer itself (Jn. 17), the aim of Jesus’ words is to bring his followers into joy.
Jesus’ desire is that his followers have Jesus-sized joy, and his words are instrumental to their own experience of his joy.
Martyn Lloyd-Jones gives some practical suggestions to how believers may have this joy. He states,
There are many Christian people who spend the whole of their lives looking at their own feelings and always taking their own spiritual pulse, their own spiritual temperature. Of course, they never find it satisfactory, and because of that they are miserable and unhappy, moaning and groaning. Now that is wrong. First and foremost we must avoid concentrating on our own feelings. We must learn to concentrate positively on ‘these things’. In other words, the secret of joy is the practice of meditation–that is the way to have this joy of the Lord. We must meditate upon him, upon what he is, what he has done, his love to us and upon God’s care for us who are his people. The Assurance of Salvation, (Wheaton, IL: Crossway, 2000), 305-306.