Nothing is more terrifying to someone with no moral values as people who possess a "code" of right and wrong -- especially if those values are taught through religion.
People who seek power do not want to acknowledge a "higher power," because it detracts from the grip they are able to have on those they "rule".
An idea wields more power in people's lives than wealth or political office. Wealth, property, possessions and political power can be taken from you, but an idea can only be given up if you choose to do so.
So, when I see people bashing ANY religious ideology as "dangerous to the Democracy," they are right. Allowing our leaders to tell us what's right and wrong -- which seems to change the higher up in the org chart you go -- is what keeps us sheep. Knowing in our hearts what's right and wrong means there is no wiggle room for evil to slip through.
I bet the people of WWII Germany knew what was happening was wrong, as is evidenced by the many plots to take Hitler and his closest staff out, but they allowed the state to dictate, rationalize and justify the atrocities they turned a blind eye toward. "The Jews are a fundamental threat to our democracy."