The Holy Spirit isn't a person. How could the believer ever be indwelt by a person?I always have difficulty understanding The Holy Spirit as a person, too. He is awfully mysterious.
Ephesians 4:30And do not grieve the Holy Spirit of God, by whom you were sealed for the day of redemption.
Isaiah 11:2And the Spirit of the Lord shall rest upon him, the Spirit of wisdom and understanding, the Spirit of counsel and might, the Spirit of knowledge and the fear of the Lord.
Neither the Nicene nor the Apostles creed say the Holy Spirit of God is a person.
Nicene Creed
I believe in one God, the Father Almighty, Maker of heaven and earth, and of all things visible and invisible.
And in one Lord Jesus Christ, the only-begotten Son of God, begotten of the Father before all worlds; God of God, Light of Light, very God of very God; begotten, not made, being of one substance with the Father, by whom all things were made.
Who, for us men for our salvation, came down from heaven, and was incarnate by the Holy Spirit of the virgin Mary, and was made man; and was crucified also for us under Pontius Pilate; He suffered and was buried; and the third day He rose again, according to the Scriptures; and ascended into heaven, and sits on the right hand of the Father; and He shall come again, with glory, to judge the quick and the dead; whose kingdom shall have no end.
And I believe in the Holy Ghost, the Lord and Giver of Life; who proceeds from the Father [and the Son]; who with the Father and the Son together is worshipped and glorified; who spoke by the prophets.
And I believe one holy catholic and apostolic Church. I acknowledge one baptism for the remission of sins; and I look for the resurrection of the dead, and the life of the world to come. Amen.
I believe in God, the Father Almighty,
the Maker of heaven and earth,
and in Jesus Christ, His only Son, our Lord:
Who was conceived by the Holy Ghost,
born of the virgin Mary,
suffered under Pontius Pilate,
was crucified, dead, and buried;
He descended into hell.
The third day He arose again from the dead;
He ascended into heaven,
and sitteth on the right hand of God the Father Almighty;
from thence he shall come to judge the quick and the dead.
I believe in the Holy Ghost;
the holy catholic church;
the communion of saints;
the forgiveness of sins;
the resurrection of the body;
and the life everlasting.
Amen.