The Spirit is fully God
We are five years away from the 1,700th anniversary of the Council of Nicaea that was designed to bring an end to what historians call the Arian controversy.
This was the controversy engendered by the denial of the deity of both the Lord Jesus and the Holy Spirit by an Alexandrian elder named Arius in the late 310s. Instead, the Council initiated a further 60 years of intense theological reflection and controversy. It led eventually to the promulgation of the Creed of Constantinople (381) in which the full divinity of Christ and His Spirit are confessed, and, implicitly, the formula – one God in three persons – taken as essential grammar for our speaking about God.