We would not see water baptism as being circumcision being brought over intot he New Covenant as a sign of being among the Covenant people of God, as we would see the admonition in the NT being always upon believe in the Lord jesus, and then be saved, as the Baptism would be symbolic type , as an outward sign of what was already internally done by God on our behalf!
That is why we Baptists modify the WCF on this subject!