In the Old Testament, the Holy Spirit was active in and upon people but most folks did not have a personal experience and personal realization of God being with/in them. There was a "special" class of people upon whom the Spirit came and released His gifts and anointing. Often the gift was prophecy as in the case of Saul (
1 Samuel 10:6-10) or the elders in
Exodus 11:16-30) but some times it was wisdom or miracles or special gifting as with Bezaleel in
Exodus 35:30-35. The prophet Joel foretold a time when God would pour out His Spirit on "all" flesh and men, women, servants, and handmaidens would all prophesy (
Joel 2:23-32). Not just a few people with special offices but the outpouring would be available universally. This began to be fulfilled in Jerusalem in AD 30 on the Day of Pentecost as described in Acts chapter 2. Peter quoted from Joel's prophecy to explain what was going on. What's neat about the New Testament is that the Holy Spirit's baptism, empowering, and releasing of gifts is available for ALL. And just as those who were filled with the Spirit in the Old Testament were used by God in signs, miracles, gifts, etc, now in the New Testament we can all be used that way through the Holy Ghost Baptism.