In the liturgy of the church we frequently hear the words, "In the name of the Father, and of the Son, and of the Holy Ghost, amen." This expression is a trinitarian formula that ascribes deity to all three persons in the Godhead.
Likewise, we sing the Gloria:
Glory be to the Father, and to the Son, and to the Holy Ghost.
As it was in the beginning, is now, and ever shall be, world without end. Amen.
This song ascribes eternal glory to all three persons of the Trinity. The Holy Ghost is ascribed eternal glory along with the Father and the Son.
While the deity of Christ has been debated for centuries, and the debate continues today, the deity of the Holy Spirit is generally accepted in the church. Perhaps the reason the deity of the Holy Spirit has not been very controversial is because the Spirit never took on human form.
The Bible clearly represents the Holy Spirit as possessing divine attributes and exercising divine authority. Since the fourth century, nearly all who agree that the Spirit is a person also agree that He is divine.
In the Old Testament what is said of God is also often said of the Spirit of God. The expressions "God said" and "the Spirit said" are repeatedly interchanged. In the New Testament this pattern continues, perhaps no more forcefully than in Acts 5:3-4, where Peter said, "Ananias, why has Satan filled your heart to lie to the Holy Spirit and keep back part of the price of the land for yourself? . . . You have not lied to men but to God." Simply put, lying to the Holy Spirit is lying to God Himself.
Scripture also ascribes divine attributes to the Holy Spirit. Paul writes of the Spirit's omniscience in 1 Corinthians 2:10-11, "The Spirit searches all things, yes, the deep things of God. For what man knows the things of a man except the spirit of the man which is in him? Even so no one knows the things of God except the Spirit of God." The psalmist attests to the omnipresence of the Spirit in Psalm 139:7-8: "Where can I go from Your Spirit? Or where can I flee from Your presence? If I ascend unto heaven, You are there; if I make my bed in hell, behold, You are there." The Spirit also works in creation, hovering over the face of the waters (Genesis 1:1-2).
As a concluding statement on the deity of the Holy Spirit, we have Paul's benediction in his second letter to the Corinthians, "The grace of the Lord Jesus Christ, and the love of God, and the communion of the Holy Spirit be with you all. Amen" (2 Corinthians 13:14).