This article summarizes a York University study exploring how anxiety can lead to religious extremism. I can believe that. From a psychological perspective, when we are anxious, we tend to often take more solid, definable views. That, by its nature, reduces anxiety because it reduce the ambiguity and the unknown.
If anxiety on its own can lead to religious extremism, then faith-related anxiety can definitely lead to more extreme views that happen to be self-soothing because they leave less room for error. This emphasizes the importance of being about to more positively manage and cope with religious anxiety.
In fact, we should embrace that anxiety. BioLogos hosted a nice post on this matter, discusses how doubt can lead to a deepening of one's faith through challenging our social constructions of God that prevent us from having a true relationship with the real, authentic God. This echoes Tillich's quote from The Courage to Be that is the motto of this blog: "The courage to be is rooted in the God who appears when God has disappeared in the anxiety of doubt."
Jonathan Brink also wrote a nice post on the idea of certainty and how defending certainty rarely works out for good. While it is important to be certain of some things, the best thing we can do is love others. I particularly love his quote, "The truest defense of the faith is not a defense of the faith but the act of love."