THE HOLY GHOST (OR SPIRIT) IS PART OF THE HOLY TRINITY WITH THE FATHER AND SON.
The Holy Ghost is a Spirit of God.
In the Old Testament the Hebrew word 
(ruwach, pronounced roo’-akh) was used when talking about the Spirit. This word literally means WIND, even the wind associated with a BREATHE! In the New Testament the Greek word 
(pneuma, pronounced pnyoo’-mah) was used which means the BREATHE or a BREEZE! We can literally think of the Holy Spirit as the “Breathe of God!”
Most Christians today understand Jesus the Son, and God the Father as two very distinct beings within the Godhead; however, there has been much confusion over the identity of the Holy Spirit. Perhaps some of this dates back to the King James translation of the Bible where the word “Spirit” or “Ghost” was used instead of “Breathe” or “Wind” of God.
In any case, many people throughout the ages have thought of the Holy Spirit more as a thing than a living being. Nothing could be further from the truth, and in fact as we begin to know the being of the Holy Spirit we will want to have a closer relationship with Him just as we would the Father or Son.
Although the word Trinity is not mentioned in the Bible, we know God is three in one. There are three very distinct beings that make up the Godhead.
UNDERSTANDING THE GODHEAD
Many people find it difficult to conceive how there can be three 3 different aspects of God, yet He is one.
A simple way of explaining it is to think of an ice cube. Upon coming into contact with heat, the ice will begin to melt and evaporate. During this process, that single cube of ice will simultaneously be in three forms: it will be ice, water, and a vapor.
Though the ice cube is in three different states, they all derived from the single ice cube. God is far more complex than an ice cube but this example helps you realize how our God can simultaneously be in 3 different forms.
THEY (THE FATHER, SON AND HOLY SPIRIT) ARE ALL
Omnipotent – All powerful. Luke 1:35 And the angel answered and said unto her, The Holy Ghost shall come upon thee, and the power of the Highest shall overshadow thee: therefore also that holy thing which shall be born of thee shall be called the Son of God.
Omnipresent – At all places at once. Psalms 139:7 Whither shall I go from thy spirit? or whither shall I flee from thy presence?
Omniscient – All knowing. 1 Corinthians 2:10 But God hath revealed them unto us by his Spirit: for the Spirit searcheth all things, yea, the deep things of God.
Eternal – Hebrews 9:14 How much more shall the blood of Christ, who through the eternal Spirit offered himself without spot to God, purge your conscience from dead works to serve the living God?
Equal – Acts 5:3-4 But Peter said, Ananias, why hath Satan filled thine heart to lie to the Holy Ghost, and to keep back part of the price of the land? Whiles it remained, was it not thine own? and after it was sold, was it not in thine own power? why hast thou conceived this thing in thine heart? thou hast not lied unto men, but unto God.
NEVER BLASPHEMY THE HOLY GHOST
Matthew 12:31, 32 Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men: but the blasphemy against the Holy Ghost shall not be forgiven unto men. And whosoever speaketh a word against the Son of man, it shall be forgiven him: but whosoever speaketh against the Holy Ghost, it shall not be forgiven him, neither in this world, neither in the world to come.
THE HOLY SPIRIT WAS PART OF ALL THINGS, FROM THE VERY BEGINNING OF SCRIPTURE TO THE VERY END OF SCRIPTURE
Genesis 1:1 In the beginning God (elohiym (pronounced el-o-heem’) created the heaven and the earth.
- Elohiym is the plural form of God. Therefore, as scripture was inspired and man began to write the Word, it was evident to the writers that God was made of more than 1 Person but at the same time there was one Godhead.
Genesis 1:2 And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.
Job 26:13 By his spirit he hath garnished the heavens; his hand hath formed the crooked serpent.
Psalm 104:30 Thou sendest forth thy spirit, they are created: and thou renewest the face of the earth.
THERE ARE MANY SCRIPTURAL REFERENCES THAT SHOW THE COEXISTENCE OF THE ENTITIES WITHIN THE TRINITY
Luke 3:22 And the Holy Ghost descended in a bodily shape like a dove upon him, and a voice came from heaven, which said, Thou art my beloved Son; in thee I am well pleased.
- Here we see the evidence of the Father, Son, and Holy Spirit all mentioned within one verse. We also see the same reference elsewhere in the Gospels.
Mark 1:10-13 And straightway coming up out of the water, he saw the heavens opened, and the Spirit like a dove descending upon him: And there came a voice from heaven, saying, Thou art my beloved Son, in whom I am well pleased. And immediately the spirit driveth him into the wilderness. And he was there in the wilderness forty days, tempted of Satan; and was with the wild beasts; and the angels ministered unto him.
Psalm 139:7 Whither shall I go from thy spirit? or whither shall I flee from thy presence?
Ephesians 2:17-18 And came and preached peace to you which were afar off, and to them that were nigh. For through Him we both have access by one Spirit unto the Father.
Acts 17:29 Forasmuch then as we are the offspring of God, we ought not to think that the Godhead is like unto gold, or silver, or stone, graven by art and man’s device.
1 Corinthians 2:10-11 But God hath revealed them unto us by his Spirit: for the Spirit searcheth all things, yea, the deep things of God. For what man knoweth the things of a man, save the spirit of man which is in him? even so the things of God knoweth no man, but the Spirit of God.
IT IS IMPORTANT TO UNDERSTAND THE HOLY SPIRIT IS TRULY GOD BECAUSE OF THE FACT THAT IF WE ARE BORN AGAIN HE LIVES IN US.
1 Corinthians 6:19 What? know ye not that your body is the temple of the Holy Ghost which is in you, which ye have of God, and ye are not your own?
John 14:26 But the Comforter, which is the Holy Ghost, whom the Father will send in my name, he shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you.
The Holy Spirit has intellect. 1 Corinthians 2:10 But God hath revealed them unto us by his Spirit: for the Spirit searcheth all things, yea, the deep things of God.
The Holy Spirit has knowledge. 1 Corinthians 2:11 For what man knoweth the things of a man, save the spirit of man which is in him? even so the things of God knoweth no man, but the Spirit of God.
The Holy Spirit has emotions. Ephesians 4:30 And grieve (lupeo (pronounced loo-peh’-o)); to make sad or sorrowful, heavy of heart) not the holy Spirit of God, whereby ye are sealed unto the day of redemption.
The Holy Spirit has his own will and he makes decisions. Acts 16:6 Now when they had gone throughout Phrygia (pronounced froog-ee’-ah) and the region of Galatia, and were forbidden of the Holy Ghost to preach the word in Asia,
The Holy Spirit Loves. Romans 15:30 Now I beseech you, brethren, for the Lord Jesus Christ’s sake, and for the love of the Spirit, that ye strive together with me in your prayers to God for me;
THINGS ONLY A LIVING BEING/PERSON WOULD DO (A FORCE OR THING DOES NOT)
1) He teaches you things about God and yourself. John 14:26 But the Comforter, which is the Holy Ghost, whom the Father will send in my name, he shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you.
2) He tells the truth. John 15:26 But when the Comforter is come, whom I will send unto you from the Father, even the Spirit of truth, which proceedeth from the Father, he shall testify of me:
3) He guides. John 16:13 Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come.
4) He convinces. John 16:8 And when he is come, he will reprove the world of sin, and of righteousness, and of judgment:
5) He prays for you. Romans 8:26-27 Likewise the Spirit also helpeth our infirmities: for we know not what we should pray for as we ought: but the Spirit itself maketh intercession for us with groanings which cannot be uttered. And he that searcheth the hearts knoweth what is the mind of the Spirit, because he maketh intercession for the saints according to the will of God.
6) He commands. Acts 13:2 As they ministered to the Lord, and fasted, the Holy Ghost said, Separate me Barnabas and Saul for the work whereunto I have called them.
Sources: The Bible, TheHolySpirit.com, ChristianAnswers.net
