The beliefs of United (and my belief) on the holy spirit is stated here from Fundamental Beliefs:
We believe in the Holy Spirit, as the Spirit of God and of Christ Jesus. The Holy Spirit is the power of God and the Spirit of life eternal (2 Timothy 1:7; Ephesians 4:6; 1 Corinthians 8:6; John 1:1-4; Colossians 1:16).
The early church certainly didn't regard the holy spirit as a separate person in the Godhead other than the God the father and Christ. In fact, this teaching didn't become part of "official" tradition of the church until the council of Constantinople in 381 AD.
The bible is abundantly clear that the picture of the beings in the Godhead are the father and son:
Joh 1:1 In the beginning was the Word, and the Word was with God, and the Word was God.
Joh 1:2 The same was in the beginning with God
A picture of the Godhead. No being called "the holy spirit" is present.
Dan 7:13 I saw in the night visions, and, behold, one like the Son of man came with the clouds of heaven, and came to the Ancient of days, and they brought him near before him.
A vision from the old testament matches up with the new testament. Again no holy spirit there.
Again:
Rev 22:1 And he showed me a pure river of water of life, clear as crystal, proceeding out of the throne of God and of the Lamb.
The throne of God and the lamb. No throne for the holy spirit.
Col 3:1 If ye then be risen with Christ, seek those things which are above, where Christ sitteth on the right hand of God.
No crown or throne for the holy spirit.
Now don't get me wrong. The holy spirit is a wonderful thing. A vital thing. It's the presence of God in our universe. It's his active working, his active presence. But it's not a mythical "3rd" person in the Godhead.
Councils are often called to clarify belief in response to heresy, not make belief out of the cloth. The First Council of Constatninople met in 381 AD in response to the heresy of Arianism, and that of the "Macedonian" (the group, not the ethnicity). By denying the Godhead of the Holy Ghost, you are, in effect, neo-Macedonian.