Regarding the Continuity of the Role of the Holy Spirit in All Ages

One of the first passages mentioned in this discussion is Acts 2 and its reference to Joel 2.  The first thing I would say is that the purpose of the Pentecost event recorded in Acts 2 was to show the Jews that the Holy Spirit was going to be poured out on all nations, not just the Jewish nation.  It was a scandal to the Jews in Peter's day to think that someone could receive covenant blessings without first becoming a Jew, being circumcised.  The category they had for Holy Spirit indwelling had nothing to do with persons outside of the covenant.  So when they saw that individuals on the day of Pentecost were being filled with the Spirit, Peter had to explain that this day was prophesied by Joel; Peter told them the meaning of Joel chapter 2, and that (at least in part) it was fulfilled on that day when God poured out His Spirit, not just on believing Jews, but even on  uncircumcised believers from other nations.  The role of the Spirit in the New Covenant is primarily different in His scope, and only secondarily in extent.  In other words, the difference is primarily one of  a quantity of participants and secondarily one of a quality of experience.

Covenant Theology does affirm a measure of discontinuity between the role of the Holy Spirit in the Old and New Testaments.  Read this quote from D.A. Carson below,

"...the pulsating New Testament stance, especially strong in Paul, that sees the Holy Spirit in the life of the Christian and the church as the decisive evidence that the new age has dawned and the messianic reign has begun. The structure of New Testament eschatology is jeopardized by the failure to discern such distinctions."

But, Covenant Theology also submits that unless one has been translated from death to life by the Holy Spirit's work, he is not saved, regenerated, made right before God.