Jesus talked about the promise of the Holy Ghost in the book of John.
John 14:16-18 NKJV
And I will pray the Father, and He will give you another Helper, that He may abide with you forever— the Spirit of truth, whom the world cannot receive, because it neither sees Him nor knows Him; but you know Him, for He dwells with you and will be in you. I will not leave you orphans; I will come to you.But
John 14:26 NKJV
the Helper, the Holy Spirit, whom the Father will send in My name, He will teach you all things, and bring to your remembrance all things that I said to you.
