The Supreme Court under Chief Justice Rehnquist applied a "neutrality principle" when deciding cases involving the free exercise of religion (the First Amendment states, "Congress shall make no law...prohibiting the free exercise [of religion]"). The court argued that if a law is applied neutrally with regard to religion, then it's not a violation of free exercise. For instance, in Oregon v. Smith (1990), Smith (a state employee) was fired after a drug test found peyote (a banned hallucinogenic) in his system. Smith argued that since he consumed the peyote as part of a religious ritual at his Native American Church, he was protected by the Free Exercise Clause. The Court decided in favor of the state, arguing that since the law is applied neutrally (no religious group is allowed to take peyote) it is not a violation of free exercise.It seems to me to be self-contradicting to say that their faith practices should not be regulated by the state and then say that abuse of minors shouldn't be tolerated when that is apparently part of their faith practices. (Note - I'm not advocating their practice. I'm trying to critique your argument.)Perhaps you could elaborate - which practices should be illegal and based on what standards? In some cultures, 13 is the age of accountability and sex with your 13 year old wife is not considered child abuse. How is it that your standards of behavior are superior to theirs that you can make their practice illegal? Perhaps a "sacrificing rubber chickens" argument might be more tasteful and less emotionally charged, but I think you can see my point.
The problem with this line of thinking, in my view, is that it severely weakens the free exercise clause. If our religious freedom doesn't make accomodations for minority faiths, then we don't have much religious freedom. The Court even acknowledged in its Smith opinion that the neutrality principle will be particularly burdensome for minority religions. The NYT article on religious freedom in Russia seemed eerily familiar. Isn't the Russian government making a neutrality argument? "We aren't restricting religious freedom, because we require the same of all religions," is its basic argument.
So, what's the alternative? I consider myself an Accommodationist with regard to free exercise. Accommodationists argue that, as long as it does not place an "undue burden" upon the state, the law should make accommodations for religions that happen to break the law in their religious practice. I realize this isn't as easy to apply as the neutrality principle, for "undue burden" is a gray area (the polygamists, and age of consent, are a cases in point), but it offers our best opportunity to maintain religious freedom for the largest number of citizens.
On a side note: the Supreme Court has been heading in a more accommodationist direction under Chief Justice Roberts, see Gonzales v. O Centro, for instance.