Raphael Magarik defends male genital mutilation on religious grounds:
Judaism, at its core, posits that the central facts of a person’s identity, a person’s core existential commitments, are not chosen. You don’t get to choose whether you’re Jewish. This flies against an American tradition of radical autonomy, one that dates, if not to Roger Williams, at least to Walt Whitman.
… [T]he point of Judaism is to make something of your past. If a Jew doesn’t have that past, she is missing out. If you haven’t been bored by learning Talmud, you’ll probably never be enchanted. If your grandparents didn’t practice Judaism, you miss out on local, idiosyncratic customs: this way of wrapping tefillin, that of making Kiddush. If your body hasn’t been marked as Jewish, you’ll never have quite the same identification with the Jewish people. None of these things are your choice, but they are crucial to making your choices meaningful. So if my parents hadn’t circumcised me, I’d feel they’d robbed me of my birthright.
All one can say is that if this is the definition of religion – that it's unchosen, mandatory and involves permanent markings of the body – then liberal individualism is going to have a hard time digesting it.