Only when the hour has arrived for his glorification does Jesus promise the coming of the Holy Spirit, since his Death and Resurrection will fulfill the promise made to the fathers. The Spirit of truth, the other Paraclete, will be given by the Father in answer to Jesus' prayer; he will be sent by the Father in Jesus' name; and Jesus will send him from the Father's side, since he comes from the Father. The Holy Spirit will come and we shall know him; he will be with us for ever; he will remain with us. The Spirit will teach us everything, remind us of all that Christ said to us and bear witness to him. The Holy Spirit will lead us into all truth and will glorify Christ. He will prove the world wrong about sin, righteousness, and judgment.
-- CCC 729