If I do not go, the Advocate will not come to you

Jesus said to his disciples:
"Now I am going to the one who sent me,
and not one of you asks me, 'Where are you going?'
But because I told you this, grief has filled your hearts.
But I tell you the truth, it is better for you that I go.
For if I do not go, the Advocate will not come to you.
But if I go, I will send him to you.
And when he comes he will convict the world
in regard to sin and righteousness and condemnation:
sin, because they do not believe in me;
righteousness, because I am going to the Father
and you will no longer see me;
condemnation, because the ruler of this world has been condemned."
(Jn 16:5-11)