The promises that Jesus makes to us as we come to Pentecost grows ever more mysterious and deep. John spent a lifetime reflecting on the word of God before he wrote his gospel and in these passages we see the result of that experience and reflection.
The last phrase of today's writing, "and that joy no one shall take from you. When that day comes you will not ask me any questions." When the Spirit comes, all the questions about Jesus, who he is, what he meant, why he died, they all stop; from then on the living, risen Jesus is all the Apostles shall need. These promises are still for us today. When we enter the life of the Spirit we are content simply to know Jesus.