Dr. James Hamilton’s book, God’s Indwelling Presence: The Holy Spirit in the Old and New Testaments, seeks to prove that OT believers were not indwelt with the Holy Spirit unlike NT believers after Christ’s resurrection.
It’s important to note that Dr. Hamilton draws a distinction between regeneration, which he believes the Spirit actively participates in giving life to the hearts of both OT and NT believers and indwelling of the Spirit, which he concludes only occurs in NT believers after the resurrection.
I believe the upshot of this book is that it stresses the dramatic shift in salvation history caused by the death and resurrection of Christ. Where once God's presence and salvation was located in Jerusalem (Temple) but now it's located in God's people by faith in Christ. Hamilton rightly notes this implication in his last chapter entitled "Results and Relevance for Today" (pg. 161-169)
Dr. Hamilton’s book is grounded in convincing exegesis and I found most of my questions against his thesis answered. So if you want to learn more about the Holy Spirit, you should definitely get this book.