Why does the Coptic church still perform circumcisions?

Circumcision is a requirement from The Mosaic Law: > Any uncircumcised male who has not been circumcised in the flesh of > his foreskin will be cut off from his people – he has failed to carry > out my requirement. *(Gen. 17:14, NIV)* However the old laws are no longer a requirement based on being saved by grace. > For it is by grace you have been saved, through faith--and this is not > from yourselves, it is the gift of God *(Ephesians 2:8, NIV)* I understand that the Coptic Orthodox Church still practices circumcision. What is the Biblical basis for this?