sent to indwell, guide, teach, empower the believer

But when He, the Spirit of truth, comes, He will guide you into all the truth; for He will not speak on His own initiative, but whatever He hears, He will speak; and He will disclose to you what is to come.

And after He had said these things, He was lifted up while they were looking on, and a cloud received Him out of their sight.

John 16:13 and Acts 1:9