“But when the Helper comes, whom I will send to you from the Father, the Spirit of truth, who proceeds from the Father, he will bear witness about me.  And you also will bear witness, because you have been with me from the beginning. (ESV)
 But I have said these things to you, that when their hour comes you may remember that I told them to you.
The Work of the Holy Spirit
“I did not say these things to you from the beginning, because I was with you.  But now I am going to him who sent me, and none of you asks me, ‘Where are you going?’  But because I have said these things to you, sorrow has filled your heart.  Nevertheless, I tell you the truth: it is to your advantage that I go away, for if I do not go away, the Helper will not come to you. But if I go, I will send him to you.  And when he comes, he will convict the world concerning sin and righteousness and judgment:  concerning sin, because they do not believe in me;  concerning righteousness, because I go to the Father, and you will see me no longer;  concerning judgment, because the ruler of this world is judged.
 “I still have many things to say to you, but you cannot bear them now.  When the Spirit of truth comes, he will guide you into all the truth, for he will not speak on his own authority, but whatever he hears he will speak, and he will declare to you the things that are to come.  He will glorify me, for he will take what is mine and declare it to you.  All that the Father has is mine; therefore I said that he will take what is mine and declare it to you. (ESV)