Justin Taylor:
Reformed theologians historically have held to a “covenant of works” (or covenant of creation) between God and Adam. Many evangelical scholars today deny that such a thing existed. I believe that it does.
This following questions and answers cannot do justice to the relative complexity of the debate, but perhaps it will be helpful for the theologically inclined to see why some of us do believe that the Bible teaches there was such a covenant with Adam.
Was there a covenant between God and Adam?
A fruitful way to answer that is by examining the two most common objections to the presence of a covenant in the garden: (1) The Hebrew word for covenant isn’t found in Genesis 2-3 (it doesn’t show up until Genesis 6:18); (2) Covenants have to have either explicit oaths or ratification ceremonies (like animal ceremonies in Genesis 15:7-21), but this is not found in Genesis 2-3.
Read more here.