Understanding the Spirit of God and the Spirit of Christ in the gospels is challenging for many.
First, because two holy spirits are described: the Spirit of Christ that came upon Mary and the Spirit of God that was first put on Christ. Both are called “holy spirit.”
In Luke 1:35, the angel Gabriel told Mary that “holy spirit” and the power of the Most High would come upon her. This holy spirit was the Spirit of Christ. The power of God was the Spirit of prophecy from before the Lord. In verse 46, Mary began to prophesy and exalt the Lord.
The holy spirit on Mary was also in Elizabeth and John the Baptist.
It is also difficult for many to understand how the Spirit of Christ can be manifest in Christ and still be active in other people.
Paul said that Christ was only “found in appearance as a man” (Philippians 2:8) “revealed in the flesh” (1 Timothy 3:16)—just as the Spirit of Christ was only found in appearance as an angel in the Old Testament. This was dramatically illustrated in Revelation 1, where Christ appeared as the Angel of God and the Son of Man at the same time. Later, He appeared in the form of different angels.
Another challenge in the gospels is that the expression “the Spirit” described the Spirit of God that came on Christ and led Him into the wilderness, and Jesus used the expression “the Spirit” to describe the Spirit of Christ in the kingdom of heaven, beginning in Matthew 5:2, “Blessed are the poor in the Spirit (τῷ πνεύματι) for theirs is the kingdom of heaven.”
The Spirit of God was not called “spirit” until Jesus was made the Lord. Jesus was still “the Word.”