"The first thing Scripture says about joy can be summed up in the beginning of the hymn Jesu meine Freude [Jesus, my joy]. This is the keynote of the biblical proclamation of the birth of Christ, of the advent of the kingdom of God in the fellowship of Jesus with his disciples, of his resurrection and ascension. (Lk 2:10; Mk 2:19; Lk 24:41,52; Joh 20:20). God wants to make us glad through Jesus Christ. He does not want to depress us or shoulder us with problems, he does not want to present us with insoluble problems, but he wants us to rejoice in Jesus Christ and his rule...This belongs to the simple things which we like to forget as we are engrossed in the difficult things, namely that we learn to be chuffed about Jesus like children. Is it not the worst case of ingratitude and obduracy of heart, if the one who came for our salvation, for deliverance, now becomes a burden to us? If our joy in Christ dwindles away, so does our love for him. Without joy in the Son of God who became man and rose from the dead we get into grumbling, dissent and sadness. But how do we find such joy? Only through the firm belief: Jesus lives! If it is really true that Jesus lives, that he testifies himself to us, guides and helps us, how can we be other than glad like the disciples when they saw him on Easter Day? (Joh 20:20)
Those who have found Christ walk their way with joy, in their joy they go and sell all that they have and buy the precious pearl (Mt 13:44 [cf. v.46]). Those who do not walk the way of Jesus become sorrowful like the rich young man (Mt 19:22). Those who commit themselves entirely to the way of Jesus will become glad in it. Such joy proves itself also in the suffering which this way can bring for us (Mt 5:12; 1. Pet 4:13ff; 2. Cor 6, 10; Phil 2:17; Col 1:24; Heb 10:24 et al.). The basis of all such joy is the nearness of Jesus (Phil 4:4). Ach, mein Herr Jesu, dein Nahesein... [My dear Lord Jesus, your closeness...]. At the same time there is the confidence that it is exactly in this way that the work of Jesus Christ on earth is fulfilled and completed (2 Tim 2:10). Thus the things that should bring us affliction and annihilation, by God’s wonderful grace, only strengthen our joy. If we remain in the proper joy, then it is really true: ‘No one will take your joy from you’ (Joh 16:22) because this joy will last into eternity (1 Pet 1:8).
The church is a fellowship of joy. All rejoice in the special grace received by one (1 Cor 12:26). John does not know a higher joy that seeing his children walk in the truth (2 Joh 1:4; 3 Joh 1:4; cf 1. Cor 13:6). Paul invites his church to participate in the joy of his suffering for Jesus Christ (Phil 2:17). Jesus calls for joy with him over every sinner who repents. The whole of Lk 15 is governed by this call (15:6,9,23,32; cf 2 Cor 7:9f). Christians are a daily source of joy for one another (1 Thess 2:19; Phil 4:1). Those who have their eyes open for their fellow Christians can never lack a reason to be joyful. Isn’t it astonishing to know that not only Jesus is our joy but also our Christian brother or sister? Do we not have reason enough today to be filled with this joy?"
Dietrich Bonhoeffer, Das erste was die Schrift über die Freude sagt
 A hymn written by Johann Franck in 1650.