When looking at the post-apocalypse, ism-filled world, it is clear that all institutions that once were are no more. When thinking about the institutionsthat man has created as a means to providing a legacy for those incorporated within the system, we find that in a post-apocalypse, ism-filled world, that the idea of a legacy is foreign in its nature. So, what about the church?
The one institution that has maintained for centuries is that of the Church, or place of worship. In this season of the walking dead we find ourselves watching people as they hide away within a church, however, it is more properly described as "4 walls and a roof". When we look at the character of Maggie in this scene as she witnessed Gareth being slaughtered, along with his crew members, on his knees in front of the church alter, it is clear the she understands that the world she once knew is no more. Remember, Maggie was once a simple country girl who was raised by Hershel who was a devout Christian. We can look at the character of Maggie and what she has learned in the zombie Apocalypse and come to our conclusion of what the church is in a ism-filled world.
One thing has been clear throughout the series, that those who try desperately to hold onto parts of their life that were before the apocalypse essentially die. In my opinion, this can be said for holding onto the institution of Christianity as well. This is to say, that attempting to try and engender the "Kingdom of God" into a zombie probably wont be effective, given that they are feigning for your flesh.
When comparing Christianity to in a post-Apocalypse era to nowadays I can find distinctions between the two. This is to say, that people may treat the church as a place with good air conditioning, and a means to filling their spirit and repressing anxiety. We see the same thing in a zombie Apocalypse. The individuals in the walking dead also use the church as a means to feeling less anxious about isms and make it so they can sleep at night.