Spirit of Christ is twice used as a name for the Holy Spirit. Paul says that the Spirit of Christ is the identifying mark of people who belong to Jesus Christ. Peter makes an interesting statement. He says that the Old Testament prophets spoke of coming salvation because they had sensed the Spirit of Christ pointing centuries ahead to Jesus the Messiah (Christ).
Concerning this salvation, the prophets, who spoke of the grace that was to come to you, searched intently and with the greatest care, trying to find out the time and circumstances to which the Spirit of Christ in them was pointing when he predicted the sufferings of the Messiah and the glories that would follow. (1 Peter 1:10-11)
Spirit of Christ in Greek:
To pneuma tou Christou
Strong’s Concordance numbers: 4151, 5547
Bible references: Rom. 8:9; 1 Pet. 1:11
You are not in the flesh but in the Spirit, if indeed the Spirit of God dwells in you. Now if anyone does not have the Spirit of Christ, he is not His. (Romans 8:9 NKJV)
A similar name of the Holy Spirit is “Spirit of Jesus Christ” but there are plenty of other variations on the theme.