People hold religious, social, or any other beliefs in varying degrees. Some treat them as relative, and whimsically; belief is a matter of perspective, so everybody’s beliefs are equally true, including the changing beliefs of an individual over time. Such people are metastatically dangerous, in their way, but the more palpable threat comes from the opposite end of the spectrum: those for whom beliefs are to be so rigidly held that they cannot be questioned, even implicitly through the equal endowment of rights to speech and association.
That, in essence, is fanaticism. One can believe that Truth requires total abstinence or that Truth permits untrammeled indulgence without being a fanatic. In contrast, one can coat even moderation in fanaticism if the possibilities of both licentiousness and prudery are unspeakable.
There’s a strong whiff such negation in the preemptive removal of a Ten Commandments monument from Roger Williams Park in Providence:

CITY LAWYERS confirmed last week that they began thinking about removing the monument, given to the city in 1963 by the Fraternal Order of Eagles, after getting a complaint from a local taxpayer, A. Gregory Frazier, a former lawyer who volunteers for the ACLU. …
Given the “politically sensitive” nature of the matter, [Deputy City Solicitor Adrienne G. Southgate] says, city lawyers were happy to find a solution that would avoid litigation and at the same time spare the city the expense of removing the monument itself.
Assistant solicitor Raymond Dettore… told Raymond Bonenfant, the secretary, that the monument would have to be removed, and the Eagles could have it back if they so wished. … In August, Steven Brown, the ACLU’s executive director, reminded the city that the monument was still there and needed to be moved. Feeling anxious about the delay, Southgate directed Bob McMahon, deputy parks superintendent, to cover the monument with a tarp.
However, city solicitor Joseph M. Fernandez says that when he mentioned the tarp to Mayor Cicilline during a briefing, Cicilline blocked Southgate’s order, saying covering the Ten Commandments with a tarp didn’t seem appropriate.
Fernandez said it was the first time the Ten Commandments display came up in their conversation, and doesn’t know if the mayor knew about the plans for the monument before that day.

Perhaps it’s the direct symbolism of the case — with the monument out in the open on a substantial expanse of public land. Or perhaps it’s the way in which bare hints of lawsuits and a private group’s “reminders” brought about the swift removal of a monument that was a fixture in the park for more than four decades, almost without the awareness of a single visible elected representative. But the episode makes absolutely clear the impossibility of compromise, or even of coexistence between ideologies.
Contrast the monument’s purgation with this aspect of its history:

At first, the Eagles rejected the proposal [to send copies of the Ten Commandments to courthouses throughout the country], concerned that since there are three different versions of the commandments it might be seen as coercive or sectarian. But that changed when a group of Protestant, Jewish and Catholic laymen produced a version acceptable to all three groups.

The same general approach could accommodate other groups whose religions don’t incorporate the Decalogue at all. It would be possible for public discussion to distill the relevant significance of the monument in the public square and, identifying echoes in the other traditions, develop a solution. When the fanatical ideology demands an absence of a particular form of expression on public land, however, no such compromise is possible — only denial and disparagement, as Stan Strain, from Modesto, California, illustrated to perfection in his letter to the editor of the Providence Journal:

I object to having religious writings and objects on public land. However, I would tolerate them if the government allowed another monument of equal size next to each one, stating that Jesus Christ is a mythical figure, and those who believe in imaginary gods and demons are suffering from a form of mental illness.

A healthy society will emphasize that which is shared, or at least comparable, between the cultures that it comprises. When the only permissible compromise is the erasure of all cultural heritage, the void that remains is a monument to fanaticism.