People like this need an outlet for hostility, so they choose a well-defended position from which to attack. Reason favors an anti-religious argument, so it's easy to express hostility in the form of anti-religious arguments and expect not to lose. The idea is a subconscious hope that this will bring a sense of security (all those fights being started and won) but it never does.
Hostility is generally a sign of a life dominated by doubt and fear.
The Rev