There are always consequences for disobedience. But OT Jews were in a covenant of works. Any disobedience brought death. We are under no such covenant. The new covenant is not between man and God, but God the Father and God the Son. And it has already been fulfilled in Christ. It is administered through grace and once we are made a part of it, we are no longer under condemnation, for we have passed from death unto life already.
Circumcision was instituted prior to the OT law. Obedience to the command was an act of faith on Abraham's part . The word is clear those who were not circumcised were cut off from God; the covenant was broken.
"And God said unto Abraham, Thou shalt keep my covenant therefore, thou, and thy seed after thee in their generations.
This is my covenant, which ye shall keep, between me and you and thy seed after thee; Every man child among you shall be circumcised.
And ye shall circumcise the flesh of your foreskin; and it shall be a token of the covenant betwixt me and you.
And he that is eight days old shall be circumcised among you, every man child in your generations, he that is born in the house, or bought with money of any stranger, which is not of thy seed.
He that is born in thy house, and he that is bought with thy money, must needs be circumcised: and my covenant shall be in your flesh for an everlasting covenant.
And the uncircumcised man child whose flesh of his foreskin is not circumcised, that soul shall be cut off from his people; he hath broken my covenant." Gen 17:9-14