In John's description of the Lamb found in Revelation, who had seven horns and seven eyes, which are the seven spirits of God (seven being the number of completeness or perfection), he is telling us that THE HOLY SPIRIT OF GOD IS THE SPIRIT OF CHRIST. There are several passages that make this quite clear. Unless one is to believe that there are two different Spirits, it should be a truth easy to come to.
In Romans 8:9-11, Paul uses the terms 'the Spirit of God' and 'the Spirit of Christ' as one.
But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of His.
And if Christ be in you, the body is dead because of sin; but the spirit is life because of righteousness.
But if the Spirit of Him that raised up Jesus from the dead dwell in you, He that raised up Christ from the dead shall also quicken your mortal bodies by His Spirit that dwelleth in you.
Notice that Paul says that we are 'in the Spirit', that is we walk in a new realm, the Spirit's realm, if so be that the Spirit of God dwell in you. Then he says if any man does not have the Spirit of Christ, he does not belong to Christ. The Spirit of God dwelling in you, and having the Spirit of Christ, is pointing to the walking in and having the same Spirit, the Holy Spirit of God. And Paul goes on to say, that this Spirit that dwells in you, is the same Spirit that raised Jesus from the dead. We have not received some cheaper version or stripped down model of the Holy Spirit. God has given us His Spirit, the same Spirit of holiness which raised Jesus mortal body unto immortality. Blessed be God forever!!
Gal. 4:6
And because ye are sons, God hath sent forth the Spirit of His Son into your hearts, crying, Abba, Father.
Paul tells us that since we are sons, or inheriting children of the covenant and promise made to Abraham, He has sent forth the Spirit of His Son into our hearts. To cry 'abba', is a most intimate portrayal of the relationship between child and father. It is to cry with outstretched arms, Daddy! We share in this special relationship with God as 'daddy' because it is the Spirit of His Son in us crying out to Daddy, Father God. Have we received another Spirit besides the Holy Spirit of God into our hearts? No. The Spirit of God that came into our hearts at the moment of faith in the Son, is the same Spirit of the Son. It should be obvious that the Spirit of His Son, which was sent forth into our hearts, is the same Spirit come to dwell in us.
Eph. 4:4-6
There is One Body, and One Spirit, even as you are called in One Hope of your calling;
One Lord, One Faith, One Baptism, One God and Father of all, who is above all, and through all, and in you all.
This could be the earliest creed known. Notice that he says there is One Body, which is the Church, made up of believing Jews and Gentiles. There is ONE SPIRIT, which points to the fact that as mentioned in Scripture, the Spirit of God is synonymous with the Spirit of Christ, or the Spirit of Jesus. Also notice, that the One God and Father , is "in you all." We know that the Holy Spirit is that which dwells in the believer, and the Father dwells in the believer by His Spirit. Paul also states that "Christ dwells in your hearts by faith." So we have The Father, Christ, and the Holy Spirit dwelling in our hearts. This residence in the believer is accomplished through the One Holy Spirit.
Phil. 1:19
For I know that this shall turn to my salvation (deliverance) through your prayer, and the supply of the Spirit of Jesus Christ.
Here Paul speaks of the circumstance of his being in prison. He says that he believes that through prayer and the 'supply of the Spirit of Jesus Christ', he shall be delivered. Is Paul looking for the supply of a spirit other than the Spirit of God? Of course not. He sees the prayer of the saints and the supply of the Spirit, which is the Spirit of Jesus, as being the means of his release from prison.
I Pet. 1:11
Searching what or what manner of time the Spirit of Christ which was in them did signify, when it testified beforehand the sufferings of Christ, and the glory that should follow.
Here, Peter tells us that the Spirit which operated in the prophets, who foretold the things concerning the sufferings and the glory of the Messiah, did so by the Spirit of Messiah. The Spirit of God, which came upon the prophets of old, was the Spirit of Christ. The Spirit of God which spoke of the things concerning the Messiah, was the Spirit of Messiah. Which leads us to one last passage to look at.
John 14-16
1. 14:16-18 And I will pray the Father, and he shall give you another comforter, that He may abide with you for ever. Even the Spirit of Truth; whom the world cannot receive, because it seeth him not, neither knoweth him; but ye know him; for he dwelleth with you, and shall be in you. I will not leave you orphans; I will come to you.
2. 14:26 But the comforter, which is the Holy Spirit, 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.
3. 16:13-15 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, shall he speak; and he will shew you things to come. He shall glorify me: for he shall receive of mine, and shall shew it unto you. All things that the Father hath are mine; therefore said I, that he shall take of mine, and shall shew it unto you.
This 'comforter', or helper, that will come to abide with us forever, is the Holy Spirit. The Holy Spirit is also called the Spirit of Truth. Before this statement, Jesus just told his disciples that HE IS THE TRUTH. If He is the Truth, then it only stands to reason that the Spirit of Truth is the Spirit of Jesus, who is the Truth. It is for this reason that the Spirit, when He is come, will not speak of himself, but will glorify Jesus. All things that belong to the Father, belong to Jesus (16:15). The Spirit who comes as another Helper [of the same kind], will speak of the things of Jesus, and will glorify Jesus. The whole of the Godhead points to Jesus the Messiah, for in him dwells the fulness of the Godhead in bodily form.
Jesus promised them that he would not leave them as orphans, that is helpless and defenseless. He says, "I will come to you". This is not a reference to His physical second coming, but is His assurance of the coming of the Spirit, which was with them, and that shall be in them.
When Jesus said, "for he dwells with you", the word dwells in the gospels almost exclusively refers to location. He is living, abiding, dwelling with them at that moment. He then tells them that the One who is presently living with them, "shall be IN them". Jesus then makes his point all the more clear. He says, "I will not leave you orphans (alone and helpless), I will come to you".
Jesus equates the coming of the Holy Spirit, the Spirit of Truth, with His coming to them. This is how Christ dwells in our hearts by faith. He dwells in our hearts by the Holy Spirit, because the Holy Spirit is His Spirit. It is Him. Glory!!
Even the ancient Rabbis equated the Spirit of God, with the Spirit of Messiah. Note the following quote.
Rabbi Shim'on ben Levi explained:
"and the spirit of God hovered over the face of the waters" (Gen. 1:2), this is the spirit of King Messiah, as it is written, And the spirit of the Lord will rest upon him. By what merit will it [the Spirit of Messiah] come? . . .By the merit of repentance."1
So what is our point here? It is this. That in the Scriptures, when we see the Spirit of God, Holy Spirit (or Ghost, which is a most unfortunate translation), or the Spirit of Christ, it is referring to the same Spirit. The Spirit of God is the Spirit of Christ, because Jesus the Messiah is God.
1 Patai, Raphael. The Messiah Texts. (Detroit: Wayne State University Press, 1979), 19.