In Louis Berkhof's "Summary of Christian Doctrine" book chapter 13 on man in the covenant of grace, he has the following quote about the covenant with Abraham (underlining is mine):
(3) The covenant with Abraham marks its formal establishment. It is the beginning of the Old Testament particularistic administration of the covenant, which is now limited to Abraham and his descendants, Faith stands out prominently as its necessary requirement, and circumcision becomes its seal.
How did faith stand out prominently as the necessary requirement of the covenant?
(3) The covenant with Abraham marks its formal establishment. It is the beginning of the Old Testament particularistic administration of the covenant, which is now limited to Abraham and his descendants, Faith stands out prominently as its necessary requirement, and circumcision becomes its seal.
How did faith stand out prominently as the necessary requirement of the covenant?