Why is circumcision part of the Jewish religion? Please explain in detail according to scripture.
Answer:
Circumcision is one of the mitzvos of the Torah, as the verse states, "On the eighth day, the flesh of his foreskin shall be circumcised." Aside from this, however, it represents the covenant that was struck between God and our first Patriarch Abraham—a covenant that includes even future generations.
Circumcision is therefore a basic condition for a person to become Jewish (for male converts), and even for those born Jewish, it is one of the most fundamental and severe mitzvot, in that it represents the eternal covenant between God and Israel. It is not for nothing that the covenant applies to the organ of reproduction, for by this it represents the inner core of the person, the part that is able to embrace the entire person, and reproduce.