John 15:26-27 New Revised Standard Version (NRSV)
26 “When the Advocate[a] comes, whom I will send to you from the Father, the Spirit of truth who comes from the Father, he will testify on my behalf. 27 You also are to testify because you have been with me from the beginning.
John 16:4-15 New Revised Standard Version (NRSV)
4 But I have said these things to you so that when their hour comes you may remember that I told you about them.
The Work of the Spirit
“I did not say these things to you from the beginning, because I was with you. 5 But now I am going to him who sent me; yet none of you asks me, ‘Where are you going?’ 6 But because I have said these things to you, sorrow has filled your hearts. 7 Nevertheless I tell you the truth: it is to your advantage that I go away, for if I do not go away, the Advocate[a] will not come to you; but if I go, I will send him to you. 8 And when he comes, he will prove the world wrong about[b] sin and righteousness and judgment: 9 about sin, because they do not believe in me; 10 about righteousness, because I am going to the Father and you will see me no longer; 11 about judgment, because the ruler of this world has been condemned.
12 “I still have many things to say to you, but you cannot bear them now. 13 When the Spirit of truth comes, he will guide you into all the truth; for he will not speak on his own, but will speak whatever he hears, and he will declare to you the things that are to come. 14 He will glorify me, because he will take what is mine and declare it to you. 15 All that the Father has is mine. For this reason I said that he will take what is mine and declare it to you.