R.A. Torrey was successful as an evangelist, a pastor, a theologian, and an author. In The Baptism With The Holy Spirit he brings all four of these disciplines to bear on this major theological doctrine.
This book is fairly short, but if you take time to read all of the Scriptures that Rev. Torrey references, and if you take the time to contemplate all of his profound reasoning, there is enough here to keep you occupied for quite some time. I am a fourth generation Pentecostal (which means I grew up with these doctrines of the Holy Spirit being adhered to throughout my lifetime) and I still found quite a bit on which to think and search more deeply.
I sincerely appreciated the academic approach that Rev. Torrey brought to this book, and I would encourage anyone who wants to grow deeper in their relationship with God to take the time to really digest the material he has presented us.