“Paul’s point is that by virtue of his exaltation (resurrection and ascension) Christ, as last Adam and second man, has come into such permanent and complete possession of the Spirit that the two are equated in their activity. The two are seen as one, as they have been made one in the eschatological work of giving life to the church, that life which has its visible ‘firstfruits’ in Christ’s own resurrection.” (Richard B. Gaffin, Jr., Perspectives on Pentecost, pp. 18,19).
“As the true God by His Spirit illumines the minds of believers, enabling them to behold the glory of Christ in the gospel, so the false god of the present age has a counter-spirit at work (or is a counter spirit), which blinds the minds of the unbelieving that the light of the gospel of the glory of Christ should not dawn upon them.” (Geerhardus Vos, “The Eschatalogical Aspect of the Pauline Conception of the Spirit,” Redemptive History and Biblical Interpretation, p. 120).
(Quotes used in the Reflection for Trinity Presbyterian Church of the OPC)