Every pastor is also a theologian so let me suggest a wonderful series of books that have blessed my teaching ministry over the past 2 years.
NAC Studies in Bible & Theology
Titles include:
Believer’s Baptism: Sign of the New Covenant in Christ (a great book)
Future Israel Why Christian Anti-Judaism Must Be Challenged (another wonderful book)
God’s Indwelling Presence: The Holy Spirit in the Old And New Testaments (from what i’ve read so far, great!)
That You May Know : Assurance of Salvation in 1 John (I have not purchased this book yet)
Enthroned on Our Praise: An Old Testament Theology of Worship (I have not purchased this book yet)
Expository Thoughts 