The Greek word for "complete" is the verb "teleiow" which is often translated as "finished." The initial words of Jesus' prayer are that He wants to bring God glory on earth by "finishing" His work. This prayer is of course a foreshadowing of Jesus' final cry from the Cross in John's Gospel, "It is finished."
Specifically, what is finished? This would include His work of reconciliation, of adoption, of sacrifice, of suffering, of abandonment, of forgiveness. For you as ministers, remember, Jesus is doing this work NOT you.
PLEASE listen to me carefully apply this text to your lives, this was His work.
This is so much more than an exegetical exercise.
For either we learn to live in the "it-is-finished-ness" or you will try to complete what you think or you feel is lacking in the work of God.
If the work that Jesus has completed actually brought Glory to God, should we tamper with it? Should we add to it? Or should me simply marvel in it? Hear me, IT IS Finished.
All of you graduates have completed your internship. And you know only too well that when you take all the cares of the world and the burden of ministry upon yourself; it is exhausting beyond belief. Hear me, IT IS Finished.