The Economy of the Covenants is Witsius's magnum opus. He wrote it to promote peace amongst theologians who were divided on covenant theology. Witsius sought to be a theologian of synthesis who strove to lessen tensions between Christians.
Covenants between God and man are essentially one-sided in that they are initiated by God. However they also require human responsibility in order to be implemented. Whilst being one-sided in initiation they are two-sided in administration. God's covenants are his main means of interacting with his creation in a broad sense yet Witsius also shows that a wrong view of the covenants leads to serious error in our concepts of salvation.
This book is an outline analysis of Witsius's work. It is a companion to the original to be read in conjunction with it. Using this book you will be able to see how Witsius's arguments progress subject-by-subject. By analysing the work in outline you will be able to grasp the essence of the factors involved in explaining the origin and effects of God's covenants with his creation.