The whole purpose and meaning of the mission of Jesus is to bring joy (John 15:11; 17:13). According to John 16:20f. this was also the purpose of the sorrow which would come with His death … As we are told in John 8:56, Abraham had already rejoiced to see the day of Jesus and he saw it and was glad … In the first instance, however, both in the Johannine passages and in Luke. 10:21, this joy is the joy of Jesus Himself, His rejoicing in the Holy Ghost. Men neither appropriated it to themselves nor produced it of themselves, but it came to them in and with the man Jesus. It was given them in Him and by Him. In the first instance it was present for them objectively - and obviously identical with the kingdom of God, which is joy as well as righteousness and peace (Rom. 14:17). It was this objective joy which could and should be reproduced in the joy which they too were permitted and commanded. In the presence of the man Jesus it was already actual for them and could not be resisted or destroyed by anything or anyone, John 16.22.
Barth, K., Bromiley, G. W., & Torrance, T. F. (2004). Church dogmatics, Volume V: Index, with Aids for the Preacher. Translation of Die kirchliche Dogmatik.; Each pt. also has special t.p.; Includes indexes. (401). Edinburgh: T. & T. Clark.