Circumcised and Baptized in Christ (Colossians 2:11,12; LD 26)

We continue to consider the themes of the catechism and the issue of baptism.  In many ways it is tempting to say that circumcision is associated with the Old Testament and baptism is associated with the New Testament.  This could mean that the application of these signs are radically different.  What can we see in Scripture that shows us that these signs might have more continuity than discontinuity?  Ultimately, what should these signs be communicating to us that can be missed in the context of our discussion on infant baptism?