For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
James Kraft
Both the Holy Ghost and the Holy Spirit are one in the same. Ephesians 1:13-14 In whom ye also trusted, after ye heard the word of truth, the gospel of your salvation, (First Corinthians 15:3-4) in whom also AFTER ye believed were sealed by that Holy Spirit of promise.
Ephesians 4:30 And grieve not the Holy Spirit in whom ye are sealed unto the day of redemption.
Romans 8:9 Without the Spirit of God there is no salvation.
Matthew 7:21-23. Jesus said, I know you not. Why? They did not have His Spirit in them.
First Timothy 2:19 Nevertheless, the foundation of God is sure, having this seal, (Ephesians 1:13) the Lord knoweth them that are His. God knows His sheep because they have His Spirit in them.
Second Timothy 2:13. If we believe not, He abideth faithful, He cannot deny Himself. His Holy Spirit that lives in all believers.
John 3:18. John 10:28-29.