Religious zealots fit perfectly the psychological profile of the typical alphabet agency stooge.
They're dogmatic, conformists, traditionalists/conventionalists, authoritarians by nature (more specifically RWA[0]), malleable to chauvinistic rhetoric and propaganda, averse and hostile to opposition's rhetoric and dissenters.
That explains why these folks are attracted to these positions and why those spy agencies seek them aggressively and make no mistake some of them are very bright and innovative but unfortunately their brain is severely compartmentalized and the one chamber holding the religious and nationalist stuff is extremely deficient in terms of mental capacity and reasoning.
[0]: https://en.wikipedia.org/wiki/Right-wing_authoritarianism