Don Johnson

Here is my understanding.

Circumcision of males was the sign of a FAMILY entering Abraham’s covenant. This is one you want to be in as it is just promises from God and is therefore sometimes called the Promise.
It is a physical sign of a spiritual truth, the need for heart circumcision, which is true for everyone, males and females Some pagans also circumcized males, so JUST because one is circumcized does not mean anything, it needs to have been done in faith, as does everything that counts spiritually.

ANYONE IN CHRIST has put on Christ and so is in Abraham’s covenant and so can partake in Passover in good faith, for example, where it is required to be circumcized if male to participate.

But I do not see explicitly where the foreskin is a symbol for sin, rather removing the foreskin is a sign of being tenderized.