Circumcision
Circumcision is very important to most branches of Judaism, with over 90% of male adherents having the procedure performed as a religious obligation. The basis for its observance is found in the Torah of the Hebrew Bible, in Genesis chapter 17, in which a covenant of circumcision is made with Abraham and his descendants. Jewish circumcision is part of the "brit milah" ritual, to be performed by a specialist ritual circumciser, a "mohel", on the eighth day of a newborn son's life, with certain exceptions for poor health. Jewish law requires that the circumcision leaves the glans bare when the penis is flaccid. Converts to Conservative and Orthodox Judaism must also be circumcised; those who are already circumcised undergo a symbolic circumcision ritual. Circumcision is not required by Judaism for one to be considered Jewish, but some adherents foresee serious negative spiritual consequences if it is neglected.
Infant baptism
Covenant theologians point out that the external sign of the covenant in the Old Testament was circumcision. Circumcision was performed upon the male children of Israelites to signify their external membership in God's people, not as a guarantee of true faith; the Old Testament records many Israelites who turned from God and were punished, showing that their hearts were not truly set on serving God. So while all male Israelites had the sign of the covenant performed on them in a once off ceremony soon after birth, such a signifier was external only and not a true indicator of whether or not they would later exhibit true faith in Yahweh.