And I will ask the Father, and he will give you another Helper, to be with you forever, even the Spirit of truth, whom the world cannot receive, because it neither sees him nor knows him. You know him, for he dwells with you and will be in you.
John 14:16-17 (ESV)
The Holy Spirit is a person, not a vague spiritual force, co-equal with God in the Trinity. The Holy Spirit lives in believers, a forever present Helper who reveals the truths of Scripture to us. It is important to follow the command of Jesus to ask the Father for the Holy Spirit to increasingly fill us and work in our lives.