I assume that all would agree that Paul classified Abraham's circumcision as a work (ref book of Romans). Some people hold to the idea that baptism is not a work. However, even though circumcision and baptism are two separate and different methods of "signing the contract" of two separate and diffrent covenants, they each have similar attributes. For example, both were commandments from God. What particular attribute does circumcision have that puts it into the works category whereby baptism does not have a similar attribute that would likewise put it into the same category?