In the early 1800s, the Christian community underwent a crucial and valuable identity-check with the advent of the Unitarians. As various groups argued for reconfigurations of historic Christian doctrines, it appears that those questioning or denying the Trinity often began their critiques by undermining the historical position on the person of the Holy Spirit.

For example, in 1787 John Marsom wrote a book entitled, The Impersonality of the Holy Ghost, which—while initially unpopular—was republished in subsequent editions as the nontrinitarian sects grew. The Holy Spirit seems to be the first hurdle over which heretics will lunge when they begin departing from the Christian faith. Thus, it is crucial that Christians of every class (laymen or theologians) have a reasonably well-developed pneumatology (that is, an understanding of the Holy Spirit). With that in mind, allow a few basic explanations of who the Holy Spirit is.

The Holy Spirit is a Member of the Godhead

In orthodox Christianity, the doctrine of God is Trinitarian. This can be seen in two ways: historically and scripturally. The history is settled. Christians are Trinitarians and have been for at least 1600 years (as evidenced in the Athanasian Creed), and the very word Trinity appeared in common use by Christians within 100 years after the life of Jesus. To put it directly, denial of the Trinity is denial of Christianity.

Of more importance, however, is the scriptural support for the doctrine of the trinity. This is clearly expressed given the Trinitarian formula of Christ’s Great Commission, “Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit” (Matthew 28:19). One can also recognize the Holy Spirit’s place as a member of the Trinity through His activity in the baptism of Jesus. Matthew 3:16-17 records that when Jesus was baptized, the Holy Spirit of God descended like a dove and rested on Him, and God the Father spoke from Heaven, stating that Jesus was His “beloved Son”. Similar trinitarian formulas are found in 2 Corinthians 13:14, 1 Corinthians 12:4-6, Ephesians 4:4-6, 1 Peter 1:2, and Jude 1:20-21.

Not only is the Holy Spirit mentioned in the same likeness as the Father and the Son (as shown), but He is also treated as divine in the Scriptures. In Acts 5:3, Peter tells Ananias that Satan has filled his heart “to lie to the Holy Spirit.” In the next verse, he elaborates on this crime by saying, “you have not lied to man but to God.” The Holy Spirit, then, is identified as God.

The Holy Spirit is a Person

Christians can sometimes fall into the mistaken habit of referring to the Holy Spirit as “an it”. It would seemingly not be unthinkable to hear a Christian say, “The Holy Spirit will move in you, and it will cause you to be convicted!” But imagine the discomfort if that same person referred to their pastor as “it”. How much greater should we guard the third person of the Trinity!

God the Holy Spirit is constantly and repeatedly referred to with the masculine personal pronoun “He” rather than “it”. Jesus calls Him by this masculine personal pronoun several times (John 14:26; 15:26; 16:13-14). Paul makes a point to refer to Him with a personal pronoun in Romans 8:26, saying, “the Spirit himself intercedes for us.” So, He is not an “it”. He is a person.

The Holy Spirit Personally Acts

One may wonder, “Why does it matter if we understand the Holy Spirit to be a person or a force or power?” Or the thought may come through the mind that the Holy Spirit is simply the soul of God the Father. These ideas are not foreign to Christian history, but they simply do not work with either established Christian doctrine or the Scriptures.

The Holy Spirit is not only a unique person (eliminating any possibility of Him being considered a force or power), but He is a unique person from God the Father (eliminating any possibility of Him being considered God’s soul). This can be recognized through His personal actions. For example, He comforts, teaches, and reminds God’s people in their times of need (John 14:26). He can do this because He can not only understand us, but He can understand God (1 Corinthians 2:10-11). This shows that He is a separate person from both the humans with whom He interacts, and God the Father, as He is able to interpret and comprehend both.

He has knowledge of His own (Romans 8:27), and a will of His own (1 Corinthians 12:11), with which He evaluates the wisdom of certain courses of action (Acts 15:28). He interacts with human beings in a personal way (Acts 16:6), even performing miracles at times (Acts 8:39), and speaking at other times (Acts 8:29 and 13:2). None of these actions describe an impersonal force or power, but a unique person.

The Holy Spirit is Sent by God the Father and God the Son

Throughout the Bible, the Holy Spirit is frequently noted as being sent by God the Father or God the Son. For example, Isaiah 48:16 records “the Lord God” sending His Spirit on a particular mission, and in John 16:7, Jesus prepared His disciples for His departure by promising that He would send the Holy Spirit to them.

While historians and theologians can debate what precisely this means for how members of the Trinity relate to one another (as it has been a source of conflict since the Filioque Controversy of the 11^th century), it is true in any case to say that the Holy Spirit is sent by God the Father and God the Son, and all that He does is according to the will of the Triune God (Romans 8:27).

The Holy Spirit is Our Greatest Helper

With this purpose in mind, it should come as no shock that the Holy Spirit is our greatest helper. David famously pronounced in Psalm 139:7-8 that we would never find ourselves in a situation wherein the Holy Spirit was not with us. As a member of the Godhead, He is omnipresent. Further, being able to comprehend the thoughts of God (1 Corinthians 2:11), we can trust that He is also omniscient (all-knowing), and we will never engage in anything He is incapable of understanding. He is also said to be immensely powerful, even being accredited with empowering Christ in His incarnation (Luke 4:14).

Because He is all-powerful, all-knowing, and ever-present, we can take great comfort in the fact that the Holy Spirit is said to be our Paraclete. (John 14:16; 14:26; 15:26; 16:7) This Greek word is translated several different ways, including: “Advocate”, “Helper”, “Comforter”, and “Counselor”. Each of these are accurate renderings of the word, and all are true of what the Holy Spirit does for God’s people.

When we don’t know how to pray, “the Spirit helps us in our weakness” by interceding “for us with groanings too deep for words” (Romans 8:26). He advocates for us in unified agreement with God the Son (1 John 2:1). One way in which He serves as our advocate is by helping us to grow closer to God through convicting us of sin (John 16:8), while also empowering us to live at a higher caliber (Galatians 5:25; Ephesians 5:18).

He is even responsible for producing the fruit in God’s people that validates their relationship with Him (Galatians 5:22-23; Matthew 7:16-20). Beyond all of this, the Holy Spirit also brings us into unity with our fellow Christians (Ephesians 4:1-3), and perhaps most consequentially, He inspired the Scripture. (2 Peter 1:20-21)

The Holy Spirit is the Catalyst, Proof, and Seal of Our Salvation

Finally, the Holy Spirit is a prominent figure in the salvation of mankind. Without Him, no one would be saved because Jesus said that “unless one is born of water and the Spirit, he cannot enter the kingdom of God” (John 3:5). In that same conversation, Jesus testified that the Holy Spirit brings spiritual life to whomsoever He pleases, comparing Him to the wind which “blows where it wishes” (John 3:8). He brings about salvation through what is Biblically referred to as the “baptism of the Spirit” (1 Corinthians 12:13). This, His prerogative, is perfectly in line with His being sent by the Father (Luke 11:13) and Son (Mark 1:8) to accomplish God’s will and may explain why He is referred to as the “Spirit of grace” (Hebrews 10:29).

Upon reviving the dead sinner, the Holy Spirit begins living within the Christian and is simultaneously the proof of his/her salvation and the security of his/her salvation. Any person who does not have the Holy Spirit living in him/her does not belong to Jesus Christ (Romans 8:9). This means, by the inverse, that all believers have the Holy Spirit living within them (Acts 2:38). In fact, in Acts 19:2, Paul stumbled upon a group of individuals professing belief in Jesus, and even having been baptized in water. He asked them, “Did you receive the Holy Spirit when you believed?” They responded that they had never heard of the Holy Spirit. He went on to preach the gospel to them, baptize them anew, and confirm that they were converted through the presence of the Holy Spirit in them.

Further than simply manifesting our salvation, the Holy Spirit secures it, as He is called the one “by whom we were sealed for the day of redemption” (Ephesians 4:30). This statement refers to the royal “seal” that would be placed on possessions of the king to mark them as his own. In this case, it is said that God the Father has “sealed” His people—marking them as His own—by giving them the Holy Spirit to live within them.

Who is the Holy Spirit?

In a real sense, the Holy Spirit is the inter-advent Immanuel. He is “God with us” until the Second Coming of Christ. He is God, the third person of the Trinity, uncreated, immeasurable, eternal. He is Almighty, Lord, Unbegotten, One and not three. He is neither before nor after, greater nor smaller, than the Father or the Son, but coequal with them.

He is personal, having autonomous prerogative to act, whilst also carrying out perfectly the will of God the Father and Son who send Him. He is our greatest Helper in life, and is the catalyst, proof, and seal of our salvation. Let us say without reservation: the Holy Spirit is God.