The short answer to this question is, yes, the Holy Spirit as described in the Bible is fully God. Along with God the Father and God the Son (Jesus Christ), God the Spirit is the third member of the Godhead or the Trinity.
Those who challenge the idea that the Holy Spirit is God suggest that the Holy Spirit may simply be an impersonal force of some kind, a source of power controlled by God but not fully a person Himself. Others suggest that perhaps the Holy Spirit is just another name for Jesus, in spirit form, apart from His body.
Neither of these ideas lines up with what the Bible actually says about the Holy Spirit, though. The Bible describes the Holy Spirit as a person who has been present with the Father and the Son since before time began. The Spirit is integral to all of the things that God is described as doing in the Bible.
The Spirit of God was present at and involved in creation (Genesis 1:2; Psalm 33:6). The Holy Spirit moved the prophets of God with the words of God (2 Peter 1:21). The bodies of those in Christ are described as temples of God because the Holy Spirit is in us (1 Corinthians 6:19). Jesus was clear that to be “born again,” to become a Christian, one must be born “of the Spirit” (John 3:5).
One of the most convincing statements in the Bible about the Holy Spirit being God is found in Acts 5. When Ananias lied about the price of a piece of property, Peter said that Satan had filled Ananias’s heart to “lie to the Holy Spirit” (Acts 5:3) and concluded by saying that Ananias had “lied to God” (verse 4). Peter reveals that the Holy Spirit is God. Lying to the Holy Spirit is lying to God.
Jesus told His disciples that the Holy Spirit, the Helper, was different from Himself. The Father would send the Helper, the Spirit of truth, after Christ departed. The Spirit would speak through the disciples about Jesus (John 14:25–26; 15:26–27; 16:7–15). All three Persons Jesus mentions—Father, Son, and Holy Spirit—are God while being distinct from each other within the Trinity.
The three members of the Trinity show up, together yet distinct, at Jesus’ baptism. As Jesus comes up from the water, the Spirit descends on Him like a dove while the voice of the Father is heard from heaven saying that He is pleased with His beloved Son (Mark 1:10–11).
Finally, the Bible describes the Holy Spirit as a person, not a mere force. He can be grieved (Ephesians 4:30). He has a will (1 Corinthians 12:4-7). He uses His mind to search the deep things of God (1 Corinthians 2:10). And He has fellowship with believers (2 Corinthians 13:14). Clearly, the Spirit is a person, just as the Father and the Son are persons.
Indeed, the Bible is unequivocal that the Holy Spirit is, in fact, God, just as Jesus Christ and the Father are God.