For When he 'the Spirit of Truth' comes, he shall guide you to all Truth
'Unless I go away, the Advocate will not come to you; but if I go, I will send him to you.'

Who is this Advocate?
'holy Spirit'

When Elizabeth heard Mary’s greeting, the baby leaped in her womb, and Elizabeth was filled with the Holy Spirit. Luke 1 41

Does this fulfill the Prophecy?
The Spirit was there Before Jesus, During Jesus and After Jesus aswell.....

SO WHO IS THIS SPIRIT ' who was not there during the time of Jesus'