It seems to me that the lesson of the West is not that it is important to have religious moderates. Rather, the lesson is that it is important that religion be a private conviction, not a basis for social policy.
As soon as you say that we have to care for the poor or ban abortion because of God's will, you're making religion public. If you can, instead, make an argument for both or either based on appeals to reason and conscience, then you have the basis for public policy.
The US is getting more and more immigrants whose religion is not a product of the Protestant Revolution. Biden and Ryan are both Catholic, part of a growing number of Catholics in this country. A growing number of Muslims live here as well. I sometimes wonder if these - or even some of our more traditional Protestants - really understand our approach to religion.
A person can have what seems like extreme religious views and still be a part of this great country. Atheists seem extreme to believers and people who believe that God daily intervenes in life seem extreme to people who see God as a benevolent law-giver. There is not even a good way to judge extremism in the realm of religion.
But no one can have the conviction that their religious convictions ought to be the basis for any laws in this country. Your belief in things unseen cannot be the thing that governs the affairs of men that are seen.
Religious freedom cuts both ways. You are free to have your own religious beliefs and I am free from those same religious beliefs. The Protestant Revolution made religion a private rather than public matter. Whether that means that one's religion is moderate is also a private matter.