Promises of Jesus:
The Eternal Holy Spirit!

And I will ask the Father, and He will give you another Advocate to be with you forever the Spirit of truth. The world cannot receive Him, because it neither sees Him nor knows Him. But you do know Him, for He abides with you and will be in you. John 14:16-17

When the Advocate comes, whom I will send to you from the Father the Spirit of truth who proceeds from the Father He will testify about Me. John 15:26

And behold, I am sending the promise of My Father upon you. But remain in the city until you have been clothed with power from on high.” Luke 24:49

However, when the Spirit of truth comes, He will guide you into all truth. For He will not speak on His own, but He will speak what He hears, and He will declare to you what is to come. John 16:13