WHAT is God? WHAT is man(kind)?

The one true God is a Spirit. 

• God is a Spirit:... John 4:24.

(The Jews call Him Elohim, the one God of all.)

God is almighty and supreme. Everything was created by God as THE Father of everything; otherwise, He is not God.

• One Lord, one faith, one baptism, One God and Father of all, who is above all, and through all,... Ephesians 4:5-6.

Only God is holy, Holy, HOLY (Isaiah 6:3 and Revelation 4:8). In truth, the entire concept of holiness is of and from God as the Father.

Knowing only God is Holy by nature and God is a Spirit (John 4:24), we know God is not only a holy Spirit, He is THE Holy Spirit. 

Never forget, ALL of God IS the one and only Holy Spirit because no other Spirit is Holy, period. 

• There is one body, and one Spirit, even as ye are called in one hope of your calling;... Ephesians 4:4.

God is also love.

• …God is love. 1 John 4:8 and 16.

The God kind of love is clearly different from mankind's love. Love of/from God is holy because the source is naturally holy. Mankind's brand of love cannot be holy because the source is not naturally holy.

In the most literal sense, God gives of Himself in His love because He is literally the best of everything conceivable. Otherwise, He is not God. Therefore, the best gifts are of God and from Himself, as the one and only Holy Spirit.

• If ye then, being evil, know how to give good gifts unto your children: how much more shall your heavenly Father give the Holy Spirit to them that ask him? Luke 11:13.
• If ye then, being evil, know how to give good gifts unto your children, how much more shall your Father which is in heaven give good things to them that ask him? Matthew 7:11.

As a loving Father, explained in the next sections titled "Who is God?", God is THE Father to all who want to be His children, and His children call Him Father. 

• But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name: John 1:12.
• And call no man your father upon the earth: for one is your Father, which is in heaven. Matthew 23:9.

Unlike God, who is a Spirit-THE Holy Spirit, man is carnal and made of flesh from the elements of the earth.

• The first man is of the earth, earthy;... 1 Corinthians 15:47.

We know God is THE Holy Spirit, but WHO is He?

First, we must understand and remember that the will of God is the supreme law of the universe and all of creation because He made it and everything possible. He reveals Himself to us according to His will, as He decides. Thus, all aspects of God's persona that He chooses to use as a revelation of Himself are God, and each is part of the one and only Holy Spirit throughout time and the universe forever.

The Holy Spirit is the general term for God, but who is He specifically?

Per His will, like a true loving Father, God has revealed Himself to us in three ways. Again, each of the three ways is, by definition, a Holy Spirit and THE Holy Spirit because God is one Spirit, and each of the three individual presentations (personas) of God is God. Think of an apple pie divided into three large pieces. The whole pie is apple pie, and each piece is apple pie.

The Bible tells us the three revelations of God, the Holy Spirit, as personas and presentations so that we may come to know Him, from both:

1. The perspective of heaven (the personas); and
2. The perspective of earth (the presentations). 

When we compare the two perspectives, we find the great revelation of Himself that He intended, i.e., according to His will.

From the perspective of heaven, the Spirit realm ("God in heaven"), 

• For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one. 1 John 5:7.

The Holy Spirit (God) is individually and collectively the Father, the Word, and the Holy Ghost.

From the perspective of earth, the physical realm ("God with us on earth"), the Father said:

• Behold my servant, whom I have chosen; my beloved, in whom my soul is well pleased: I will put my spirit upon him, and he shall shew judgment to the Gentiles. Isaiah 42:1 and Matthew 12:18. 

The Father said He has a servant, a soul, and a spirit (lowercase "s" intended) by which we can know Him on earth. For now, think of the Father's spirit as truth! 

To recap, God is the Holy Spirit. The (Holy) Spirit is not human. It is made of three parts. One of those is a sense of truth called a spirit of truth inherent in it. You will learn that everyone has a sense of truth, a spirit of truth, or simply a spirit in them. Stated another way, God and man each have their own servant (something utilitarian like a body), a soul (life), and a spirit (truth).

(Note: The King James New Testament of the Bible uses both the capital "S" when referring to the Spirit of God as God being the Holy Spirit and lowercase "s" for the spirit (truth) as an element partially comprising a persona including the Father and every person, respectively. Understanding the context is important, and it's easy if we understand who and what God and man are.) 

When we hold Him at His Word and match the three personas of God (the Holy Spirit) in the heavens (in the Spirit realm) to the three presentations of God here on earth (in the physical human realm), we discover the pathway to Him. 

• Draw nigh to God, and he will draw nigh to you... James 4:8.

The Father chose the personas and presentations according to His will so that we would know Him if we chose to learn of Him, so let's do that!

"God in heaven" (i.e., the personas of God in the Spirit):

• For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one. 1 John 5:7. 

matched with

"God on earth" (i.e., the presentations of God in the physical earth):

• Behold my servant, whom I have chosen; my beloved, in whom my soul is well pleased: I will put my spirit upon him, and he shall shew judgment to the Gentiles. Isaiah 42:1 and Matthew 12:18. 

gives us this result:

• The Father = the soul (life) of God. He is THE almighty and great "I am". To us, He exists according to His will because He is God. Thus, we know the soul of God, the Father, as the Father's will because He is God and the Father (creator/originator) of everything. Whatever the Father says is a statement of His will and is or shall become.
• The Word = the servant (body) of the Father. In the beginning was the Word...and the Word was God. John 1:1.
• The Holy Ghost = the spirit (truth) of the Father. Not surprisingly, the Father's truth is also called the "Spirit of Truth" because He is absolute truth. The Spirit of Truth (Holy Ghost) bears witness to the Father's Word and evidences the Father's will in power because He is absolutely, prophetically, truthful. He teaches us all things and much more by the Spirit of Truth; see John 14:17, 15:26, 16:13, and 1 John 4:6 for starters.  

(Any modern version of the Bible that changed "Holy Ghost" to "Holy Spirit" hides the Spirit of Truth (the Holy Ghost) and confuses. This is exactly the reason why it is dangerous and foolhardy to change the Word of God to please mankind. In doing so, man displeases the Father. That is not a good idea under any circumstances. Stick with the King James Bible for the purest understanding.)

Yes. More specifically, the question is: are there scriptures that say the spirit (lower case "s" intended") of the Father is the Spirit of Truth (the Holy Ghost)? Yes.

Reproofs: The books of the New Testament written by Matthew and Mark recount many of the same events. One such event refers to the spirit (truth) of the Father as "the Spirit of your Father" (Matthew) and "the Holy Ghost" (Mark).

Compare:

• But when they shall lead you, and deliver you up, take no thought beforehand what ye shall speak, neither do ye premeditate: but whatsoever shall be given you in that hour, that speak ye: for it is not ye that speak, but the Holy Ghost. Mark 13:11.

to

• But when they deliver you up, take no thought how or what ye shall speak: for it shall be given you in that same hour what ye shall speak. For it is not ye that speak, but the Spirit of your Father which speaketh in you. Matthew 10:19-20.

See also Romans chapter 8 and 1 Corinthians chapter 2.

The authors of the King James New Testament understood the meaning, significance, and identity of the Holy Ghost as the Spirit of Truth in the context of God, the Father. They also understood the distinction between the term Holy Spirit partially comprised of the Father, the Word, and the Holy Ghost (Spirit of Truth). They always agree and bear witness to the Father's will! The same cannot be said of any "version" of the New Testament that is not the King James; beware.

Yes.

• And God said, Let us make man in our image, after our likeness: Genesis 1:26.

(The plural reference to "us" acknowledges the fact He regards Himself as a trinity of personas: the Father Himself, His Word (whatever He says), and His Truth. The Father (God) is also a trinity of presentations (servant/body, soul, and spirit) for man's recognition of his likeness to Him as explained in detail below.)

Of course, God is eternal. The Father is eternal, His Word is eternal, and His Spirit of Truth (the Holy Ghost) is eternal. Therefore, mankind must also be eternal in some way in order for us to be created in His image and likeness, because He is eternal.

In the image of God, like God, there are three personas of every person. All people have a spirit contained within a living soul and housed within a servant-their body. 

• ...and man became a living soul. Genesis 2:7.
• And the very God of peace sanctify you wholly; and I pray God your whole spirit and soul and body be preserved blameless unto the coming of our Lord Jesus Christ. 1 Thessalonians 5:23. 

Mankind has a body (his servant), a soul (life in him), and a spirit (truth in him). Therefore, if God created man in His image, God the Father must present Himself on earth, in the physical realm, as having a servant body, a soul, and a spirit like His Word says mankind has for us to know Him. He does!

In the likeness of God, man is eternal. Even though his body on earth is perishable like a piece of fruit. Man's soul is eternal. 

• And fear not them which kill the body, but are not able to kill the soul: but rather fear him which is able to destroy both soul and body in hell. Matthew 10:28.
• He that hath an ear, let him hear what the Spirit saith unto the churches; He that overcometh shall not be hurt of the second death. Revelation 2:11.
• And death and hell were cast into the lake of fire. This is the second death. Revelation 20:14.
• But the fearful, and unbelieving, and the abominable, and murderers, and whoremongers, and sorcerers, and idolaters, and all liars, shall have their part in the lake which burneth with fire and brimstone: which is the second death. Revelation 21:8.

The soul of every man (person) is the life that is given to him as a possession.

• In your patience possess ye your souls. Luke 21:19.

Thus, each of us is our own god.

• ...Is it not written in your law, I said, Ye are gods? John 10:34.
• I have said, Ye are gods;... Psalm 82:6.

God the Father wants us to know Him. We come to know Him by learning of Him. 

• Take my yoke upon you, and learn of me; for I am meek and lowly in heart: and ye shall find rest unto your souls. Matthew 11:29.

We learn of Him through His servant, His Word. 

• It is written in the prophets, And they shall be all taught of God. Every man therefore that hath heard, and hath learned of the Father, cometh unto me. John 6:45.

Jesus is the Word!

To appreciate who and what Jesus is as the first and only begotten human child of the Father (God), we must know the "nature" of the parents always determines the nature of their offspring. For example, zebras (animals) are born from zebras as animals, sparrows (birds) from sparrows as birds, perch (fish) from perch as fish, and people (humans) from people as humans. Being born of God means being born of the Spirit. Jesus was born a human child (mankind) and the Father's son (Spirit). Jesus is the ONE AND ONLY begotten (human-birthed) son of God the Father!

Recall that every person has a body (servant), soul (life), and spirit (truth). Accordingly, Jesus has a body, soul, and spirit. Jesus received His human body from His human parent, Mary His mother. He was conceived by the Holy Ghost, the Spirit of Truth, without human contact. That is how Jesus was also a son of the Holy Spirit (God).  

• Now the birth of Jesus Christ was on this wise: When as his mother Mary was espoused to Joseph, before they came together, she was found with child of the Holy Ghost. Matthew 1:18.
• But while he thought on these things, behold, the angel of the Lord appeared unto him in a dream, saying, Joseph, thou son of David, fear not to take unto thee Mary thy wife: for that which is conceived in her is of the Holy Ghost. Matthew 1:20.

The Father's spirit (truth) IS the Holy Ghost. Word of God foretold (prophesied) the coming of Christ Jesus, born of a woman and a son of God. 

From the moment of conception, Jesus's spirit was different from ours. Jesus received His spirit (truth in Him) from God as the "offspring" of the Father. Recall that the Father's Word is His servant and His offspring in the Spirit because it originates from Him. 

The Father placed Himself (His Word), presented (i.e., a presentation) inside of that human named Jesus. Therefore, the spirit (truth) of Jesus IS the Word of God from the Father. Jesus knew who He was! 

The Word (the Holy Spirit, or simply the Spirit) in Him is the very reason why Jesus IS the only begotten son of God from birth, and the only way to God.

• In the last day, that great day of the feast, Jesus stood and cried, saying, If any man thirst, let him come unto me, and drink. He that believeth on me, as the scripture hath said, out of his belly shall flow rivers of living water. (But this spake he of the Spirit, which they that believe on him should receive: for the Holy Ghost was not yet given; because that Jesus was not yet glorified.) John 7:37-39.

Simply stated, the Word of God IS the spirit/Spirit (man's truth/God's truth) inside a man.

• In the beginning was the Word, and the Word was with God, and the Word was God...And the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth. John 1:1 and 1:14.

The phrase "the Word was made flesh" (John 1:14 above) means the Word (Spirit) was given a very important flesh suit to dwell within because that which is born of the flesh is flesh and that which is born of the Spirit is spirit.

• That which is born of the flesh is flesh; and that which is born of the Spirit is spirit. John 3:6.

Jesus was born a living soul like all of us. 

Therefore, Jesus was born of mankind (flesh) and Godkind (the Holy Spirit, specifically the servant of God-His Word) in a single servant body of man. 

Jesus is both the Son of God and the Son of Man, and only He can proclaim that truth everywhere. Believing Jesus is the savior, we know that as the savior He was the servant of the Father. The Word of God gives the believer the power to become a child of God. We become a child of God through repentance. 

The Word and the Holy Ghost give the Father's children the power to do the works of God according to the Father's will.

No. There can be no faith in something that has already happened because it is a fact. Whatever happened are facts to be believed.

For example, the death of Jesus on the cross and His resurrection unto life thereafter are well-documented events of human history! In fact, most of the original disciples, more than five hundred (500) miscellaneous people who knew Jesus, and Paul (the guy who authored almost 2/3 of the New Testament) all saw Him alive days after His lifeless body was taken off the cross He was nailed to and buried in a tomb. 

• For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures; And that he was buried, and that he rose again the third day according to the scriptures: And that he was seen of Cephas, then of the twelve: After that, he was seen of above five hundred brethren at once; of whom the greater part remain unto this present, but some are fallen asleep. After that, he was seen of James; then of all the apostles. And last of all he was seen of me also, as of one born out of due time. 1 Corinthians 15:3-8.  

The events of Jesus' death and resurrection are facts to be believed.

When we believe the facts about the crucifixion and resurrection of Jesus and the promise of salvation Jesus gave us, we have the “power to become” God's sons (children) by adoption through faith in the Father's Word. Faith is belief put into action, i.e., conduct (action) in reliance on the belief. Confessing (admitting) sin and repentance from sin are the actions (conduct) of faith needed to be born again and saved when our body dies. Both, confession and repentance are required to become born again of the Spirit (saved) and live forever.