Religion doesn't supercede bodily autonomy. Period.

Your rights to practice religion ends when it starts infringing on the rights of another person. You are not entitled to harming others for your own religious needs.

You can do whatever you want with your own body in the name of religion. Just do not mutilate your own child.

Imagine if a different religion warrants cutting off the nipples of newborns, or ripping off a nail, or skinning a toe. That is how barbaric you sound when you say 'it's fine to cut off the skin of my child's penis'.