A Dissertation Concerning the End for Which God Created the World, by Jonathan Edwards
This work is perhaps the most poignant and important work we’ve come across that wrestles with the existence and purpose of creation. On so many levels this work is a chief influence on our worldview and theology. Please take the time to work through it carefully. Edwards’ thought is extremely complex in certain areas, which may require slow reading and re-reading, but it is so worth it. Here is a link to John Piper’s introduction to this work as The End is included in his book, God’s Passion for His Glory. You can read the entire book online for free at this link. For more of Edwards, check out the Jonathan Edwards Center at Yale as well as Monergism.com’s Jonathan Edwards page.

Kingdom Prologue: Genesis Foundations for a Covenantal Worldview, by Meredith G. Kline (PDF)
Meredith Kline is essentially the father of Reformed Covenantal Theology in biblical studies and biblical theology for the 20th century. He is a study unto himself, as he has put together his open stream of thinking into what used to be his notebook for classes at Gordon-Conwell Theological Seminary. It has been published both by Two Age Press and Wipf & Stock Publishers, and Two Age Press has made the PDF file available for free on their site for the past few years. Kline’s thought process can be very complex in certain places as he crafts his own terminology which becomes self-referential throughout and there are no footnotes. Very much like Edwards, this work demands slow reading and re-reading but will be gold for those interested. For more Kline, see the Meredith G. Kline Online page.

The Life of God in the Soul of Man, by Henry Scougal
This is a classic work by a little known Scotch Puritan, who died at the age of 28, about the nature of Spiritual life and the heart of true “religion”. This is a dynamite little work that has inspired the thought of many theologians, paricularly George Whitefield and John Piper. The very small Works of Henry Scougal are available for purchase through Ligonier Ministries.

Introductory Essay to John Owen’s The Death of Death in the Death of Christ, by J.I. Packer
Here is probably one of the best theological essays by J.I. Packer, who is an expert on Owen, as he whets the appetite for probably the best defense of particular redemption in the Reformed/Calvinist tradition. You can read the entire work of the Death of Death at CCEL’s website at this link. For a great introduction to John Owen’s life and works, check out www.johnowen.org.