Church security and nearly any manner of protective services commonly depends heavily on methodology and the mitigation, control and management of potentially dangerous/dangerous or unwelcomed conditions. The process of providing a "secure" environment is generally a culmination of policies, procedures, training, tactics, strategics, technology, personnel, communications, facility or venue design, access control, logistics and of course, money. Much can depend on a philosophy such as "reactive" or "proactive" as they are very different approaches toward a very similar mission.
Shooting skills are often considered to be one part of a much larger overall mechanism.. Shooting is something that can often be avoided if you do everything else right. Methods, strategics and tactics can often overcome or effectively compensate for what someone may lack in absolute shooting skills but I consider it much harder to overcome poor method, poor tactics and poor strategics with impressive shooting skill. It doesnt mean that you cant but I would consider it harder is most situations. I am a proponent of church security but I certainly hope that anyone who decides to hold themselves out as some sort of "protector" of others, will learn how to do it and seek out the proper training. Again, the gun is but one minute element.
I come from an extended family that is involved in 2 different religions and 4 different churches, each with a security team. I will say that out of the 4 churches, only one has what I would call a security mechanism. The other 3 simply have guys carrying guns. I am not involved in any of these teams but I did share some basic edicts of protection with two team members who seemed more interested in talking about red dots sights and less about what protection is actually about. I have learned to just mind my own business.