John 16:7 (KJV)

But now I go my way to him that sent me; and none of you asketh me, Whither goest thou?

But because I have said these things unto you, sorrow hath filled your heart.

Nevertheless I tell you the truth; It is expedient for you that I go away: for if I go not away, the Comforter will not come unto you; but if I depart, I will send him unto you.

And when he is come, he will reprove the world of sin, and of righteousness, and of judgment:

Of sin, because they believe not on me;