Read Genesis 17 verses 1 to 23 and answer questions on circumcision.

What was to be the significance of circumcision to Abraham's family?  To what did it bind them?

Under the New Covenant, the Old Covenant sign of circumcision is replaced by a sacrament - Something that not only signifies something but also pits that which signifies into effect.  Read Colossians 2:11-12.  What is that Sacrament, and how does it relate to circumcision?