On the Day of Pentecost, the spirit of God became the speaker for Christ, “the Spirit.”
The Spirit of Christ was the Holy Spirit that “rested” on the 70 Elders in Numbers 11. In Isaiah 11, Isaiah told us that the holy spirit on Christ would be the spirit of God.
The spirit of God was also the holy spirit that “rested” on the disciples with tongues of fire on the Day of Pentecost.
This “fire” was described by Daniel as a river of fire flowing from the Ancient of Days.
Jesus promised that when the spirit of truth comes, it will lead us into all truth; and speak only what it hears.
The spirit of God was the holy spirit in the mouths of the disciples. In Acts 2:4, the disciples spoke with “other tongues” as “the Spirit”—the Spirit of Christ—gave them “utterance” or “declaration.” The same Greek word described Peter’s declaration in verse 14, where he explained the promise of the holy spirit. Of course, this declaration was from Christ, and was spoken by the spirit of God in Peter’s mouth. Jesus said the spirit of their Father would be speaking in them.
In 1 Corinthians 12, Paul described revelations from Christ as a “manifestation of the Spirit” (1 Corinthians 12:7). The apostle John called them a “revelation of Jesus Christ” in the first Chapter of Revelation, where John told us he was “in spirit in the Lord’s Day.” The spirit of God enabled John to see and hear the Spirit of Christ and bring Christ’s message to the saints.
In 1 Corinthians 14, Paul said, “I will pray with the Spirit” (I Corinthians 14:15)—describing Christ’s intercession spoken by the holy spirit in the mouths of the saints. Paul also said, “I will sing with the Spirit.” The apostle John called this a “song of the Lamb,” a song from Christ that was sung by the holy spirit.