As anyone familiar with the KJV will notice, when speaking of the Spirit, the translators were not always consistent. The translators translated pneuma as “Spirit,” but translated pneuma hagios as “Holy Ghost.” Here are some examples where the difference can be seen within the same verse:
• Luke 4:1 And Jesus being full of the Holy Ghost returned from Jordan, and was led by the Spirit into the wilderness,
• John 1:33 And I knew him not: but he that sent me to baptize with water, the same said unto me, Upon whom thou shalt see the Spirit descending, and remaining on him, the same is he which baptizeth with the Holy Ghost.
• John 7:39 But this spake he of the Spirit, which they that believe on him should receive: for the Holy Ghost was not yet given; because that Jesus was not yet glorified.)
• Acts 2:4 And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance.
• 1 Corinthians 12:3 Wherefore I give you to understand, that no man speaking by the Spirit of God calleth Jesus accursed: and that no man can say that Jesus is the Lord, but by the Holy Ghost.
I was tempted to conclude that, for some stylistic reason or due to cultural conventions, the translators preferred to translate pneuma by itself as “Spirit,” but pneuma hagios as “Holy Ghost.” But I have discovered that they did not always translate pneuma hagios (or its Hebrew equivalent) as “Holy Ghost.” Consider these passages: