The first area of the Spirit’s work is in the process of regeneration. Another word for regeneration is “rebirth,” from which we get the concept of being “born again.” The classic proof text for this can be found in John’s gospel: “I tell you the truth, no one can see the kingdom of God unless he is born again”
The second aspect of the Spirit’s work in the Old Testament is indwelling, or filling. Here is where the major difference between the Spirit’s roles in the Old and New Testaments is apparent. The New Testament teaches the permanent indwelling of the Holy Spirit in believers