It is interesting to see the workings of a fallen society within the world of the Walking Dead. There are no more institutions, either civil government or the Church, and therefore people are left to fend for themselves. The series illustrates the veneer that is civil society; remove the societal constraints of government and the Church and people descend back into their fallen natures.
This is illustrated particularly well by the city of Woodbury. It was ruled by the seeminly benevolent “Governor;” a 40s-something man who lived a quiet life before the world fell. Before the chaos started, he probably lived a quiet life. Yet, after the fall and his rise to power he used every charm he could to remain in power: persuasion, smooth talking, threats, and murder. He is but a sample of the people we encounter in the Walking Dead; there are numerous bands of roving murderers and robbers who prey on those weaker than them.
Indeed, man’s inhumanity to man was also demonstrated in a well-known social experiment performed in 1971 called the Stanford Prison Experiment (see http://www.prisonexp.org and https://en.wikipedia.org/wiki/Stanford_prison_experiment, but be prepared for content which may be disturbing). The planned two week experiment had to be cancelled after a few days due to the brutality exhibited by those in power over those under their charge.
There is evil in the world. What retrains it outwardly is civil government, and what restrains it inwardly is God’s natural law which He has written on our hearts (we often call this our “conscience;” it’s the feeling we have when we sense something is wrong). The Church helps to remind people of natural law as well as proclaim forgiveness and mercy. In the Walking Dead we encounter a world without government and with little mercy, and it is not a world in which we would wish to live.
(Image by By Andreas Levers from Potsdam, Germany – Decay, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=5608770