Abraham Booth reminds us that Tenure in Canaan is not the same as tenure in Christ.
Philip Cary and John Owen explain how No one was saved by virtue of the Old Covenant.
Benjamin Keach, in his “The Marrow of True Justification,” explains that The Covenant of Grace is the Covenant of Works kept for us.
Benjamin Keach describes how Paul connects circumcision, not with the covenant of grace, but with The weakness and purpose of the old covenant.
In this post from Particular Voices, Benjamin Keach comments on the nature of the Sinaitic covenant as a republication, in greater detail and with specific application to national Israel, of the covenant of works made with Adam, albeit for a different purpose.
Hence in opposition to that Sinai Law which ran upon those terms Do and Live, under the dispensation of the New, we hear so often of Believe and be saved, and he which believeth have everlasting Life, Mark 16.16.
Joh.3.16, 36. Not that believing now, taketh the place of doing in the Old Covenant; for then it must be our righteousness unto Justification, Gal 3.12. Rom 10.5., whereas that which justifieth is called, the righteousness of Faith, ver.6. and Phil.3.9. and therefore Faith is distinct from that righteousness it self, is not the least Atome of it: therefore, not our believing, but the obedience of Jesus Christ, is that which cometh in the room and stead of that doing for Life intended in the Law.