Although the issue of what or who the Holy Spirit (or Holy Ghost) is cannot be considered obscure by anyone who knows the scriptures, it is still one of the least understood concepts in Christendom. The problem with that is simply this – without the Spirit of God, or the Holy Spirit, you cannot enter into the kingdom of heaven (John 3:5, Romans 8:9), you cannot possess the revelation of God (1Corinthians 2:9-10, Ephesians 1:17, 3:5, 2Peter 1:21), and you have no hope in this present world (Romans 15:13, 2Corinthians 1:22, Galatians 5:5, Ephesians 1:13).
 
Wow – that’s sobering.
 
So, without a clear understanding of what or who the Holy Spirit is, what the Spirit does, and that means for you, you are lost. While everyone who is saved is not a Bible scholar, everyone who is saved has the Spirit (Acts 2:38-40, 5:32, 19:2-6; Romans 8:9, 1Corinthians 12:12-13, Ephesians 4:30, Titus 3:5) and the Spirit confirms his presence within a person (John 3:3-6, 14:26; Acts: 1:8, 2:4, 10:44-47; Romans 8:15-16, Hebrews 10:15-16, 1John 5:6-13). So, if you believe that you are saved but you are still confused about what or who the Holy Spirit is, according to the scriptures, you could not possibly yet be saved.
 
Even more sobering, huh?
 
It becomes clear then that knowledge of the Holy Spirit is essential to Christian faith – what or who is it, do you “catch” it or “receive” it, and what is the purpose and function of the Holy Spirit? These questions must be answered scripturally in order for people who are seeking God in these last and evil days to find salvation. There are many false prophets and false doctrines in the world, so if you do not know who God is for yourself according to the scriptures, you will be lost.
 
Let’s begin our study of who or what the Holy Spirit is by first determining who or what it is not:
 
 

The Holy Spirit is NOT the Third Person in a Trinity

Despite what you may have been taught, the Holy Spirit is not the third person in “the Trinity” because the Trinity (concept of God in three persons – God the Father, the Son, and the Holy Spirit, existing as separate entities) is not a Biblical concept. While it is indeed true that God manifested himself in the flesh as Jesus Christ (John 1:1-5, 14-15, 1Timothy 3:16), manifests his presence within the physical bodies of born-again Christians as the Holy Spirit (John 7:39, 14:17, Romans 8:15, 1Corinthians 3:16), and was introduced as our heavenly Father by Jesus Christ (John 5:18, 8:15-45), God only has one person:
 
Hebrews 1:1-3

1 God, who at sundry times and in divers manners spake in time past unto the fathers by the prophets, 2 Hath in these last days spoken unto us by his Son, whom he hath appointed heir of all things, by whom also he made the worlds; 3 Who being the brightness of his glory, and the express image of his person, and upholding all things by the word of his power, when he had by himself purged our sins, sat down on the right hand of the Majesty on high;

1John 5:7

For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one.

Furthermore, the fullness of the Godhead, which is in the Greek Theios (not to be confused with Theos) and was a Greek word for deities in general, was found in Jesus Christ. This “Godhead” is not a collection of divine persons but a reference to God’s authority and power (Acts 17:29, Romans 1:20, Colossians 2:9). If you do not see the connection to the word “Godhead” and authority or power because you have been taught that the Godhead was the Trinity, consider the meaning of the word “figurehead” and compare the terms – then reread the scripture references and the meaning should become abundantly clear.
 
As we can see through scripture that the Holy Spirit is not a third person of God, since God is only one person with one personality. He manifested himself in flesh as Jesus Christ and continues to manifest his presence as the Holy Spirit in the church. He even manifested himself as a dove (John 1:32-33)! These manifestations are not separate persons, but the same God whose presence is revealed in different contexts when appropriate and necessary as determined by his own will.
 
 

The Holy Spirit is NOT an Emotional Reaction or a Religious Experience

As you may have already gathered, the Holy Spirit is not a religious term for an emotional reaction that one has when they hear the word of God. The Holy Spirit teaches (John 14:26, 1Corinthians 2:13), speaks (Mark 13:11, John 15:26, 16:13; Acts 8:29, 1Timothy 4:1, 1John 5:6), and comforts (John 14:16, 18, 26; 15:26, 16:7) – this is not an emotion, although the manifestation of the presence of God quite often produces an emotional reaction in the born-again Christian (Galatians 5:22).
 

The Holy Spirit is NOT Simply Spiritual Enlightenment

Although the indwelling and even the visitation of the Holy Spirit bring spiritual enlightenment (1Corinthians 2:10, Ephesians 3:5), this kind of enlightenment is and of itself is not the Holy Spirit. The Holy Spirit, also called the Holy Ghost, is the Spirit of God, who himself is a person (Hebrews 1:3), not a state of mind. Consider how the Holy Ghost impregnated the Virgin Mary (Matthew 1:18, Luke 1:35) – enlightenment, no matter how deep or revelatory, cannot conceive a human child. Furthermore, when the bodily form of the Holy Ghost descended upon Jesus at his baptism (Luk3e 3:22) the account in Matthew (3:16) says that “the Spirit of God” descended like a dove. It is abundantly clear that the Holy Spirit is indeed the Spirit of God himself, and as we know, God is infinitely much more than a man’s enlightenment.
 
 

Who is the Holy Spirit?

As we have seen through study of what the Holy Spirit is not, the Holy Spirit IS the Spirit of God that dwells within a person providing God consciousness and power to live up to God’s standards through grace. In order for us to be truly saved, we must have the Spirit of God living within us. There are more scriptural references to these facts; the New Testament is full of them because our salvation depends on it.