Elizabeth, on meeting the pregnant Mary, said: "the baby [John] in my womb jumped for joy" (Lk 1:44). If an unborn baby can do that, how much more can we!
The angel said to the shepherds: "Do not be afraid. I bring you good news that will cause great joy for all the people" (Lk 2:10). Jesus has caused us the greatest joy!
John the Baptist said: "The bride belongs to the bridegroom [Jesus]. The friend who attends the bridegroom [every disciple] waits and listens for him, and is full of joy when he hears the bridegroom’s voice. That joy is mine, and it is now complete" (Jn 3:29). That joy is ours and it cannot be added to!
"Do not rejoice that the spirits submit to you, but rejoice that your names are written in heaven … Jesus, full of joy through the Holy Spirit, said, 'I praise you, Father … because you have hidden these things from the wise and learned, and revealed them to little children'" (Lk 10:20-21). The bedrock of our joy is the certainty of heaven. Its fullness comes through the presence of the Holy Spirt.
"I have told you this [as the Father has loved me, so have I loved you … remain in my love] so that my joy may be in you and that your joy may be complete. Very truly I tell you, you will weep and mourn [over my death] … but your grief will turn to joy … and no one will take away your joy. In that day … my Father will give you whatever you ask in my name … Ask and you will receive, and your joy will be complete" (Jn 15:11, 16:20-24). Our joy is based on our being loved by the Trinity in the same way, and to the same extent, that they love each other!
"Father … I am coming to you now, but I say these things while I am still in the world, so that they may have the full measure of my joy within them" (Jn 17:13). Where is our joy located? At the core of our being. Whose joy is it? That of the Trinity. Is there any lack in it? No, it is complete. Yet it is ever increasing for those who long for more. Can it ever be taken away? Never.
"The women hurried away from the [empty] tomb, afraid, yet filled with joy" (Mt 28:8). I love this mix of the fear of the Lord and the joy of the Lord. We find the same mix in Neh 8:10: "Don’t be dejected and sad, for the joy of the Lord is your strength" [His joy in our love for Him, our trust in Him and our readiness to repent of our sin].
The certainly of the resurrection, later dawning on those who had been on the Emmaus road, brought them such joy that they longed to proclaim the Good News to others. "Were not our hearts burning within us while he talked with us on the road and opened the Scriptures to us?" (Lk 24:32)
After the disciples had witnessed the ascension, "they worshipped him and returned to Jerusalem with great joy" (Lk 24:52).
"Though you have not seen him, you love him; and even though you do not see him now, you believe in him and are filled with an inexpressible and glorious joy" (1Pt 1:8-9). Such joy is the fruit of our sincere love for Jesus and our total trust in Him. It is ours because of our complete dependence on Him alone.