How religion separates people based on ideology and belief system

Someone wrote in Yahoo Answers:

"If you are not sure and convicted for what you stand for, you will and can fall for anything. I cannot see, anyone, man or woman, having encountered and experienced the Love of the Lord Jesus, can attest to the salvation that they received and have had a genuine touch from God, easily go into a marriage with someone who is against Christ's diety, His Person and Work" 

The above quote is an example of how the Christian religion is separatist, elitist and sectarian in nature as it divides people based on their ideologies and belief systems. Those who adhere to the Christian religion are often divided over doctrines and may feel pressurised into pledging allegiance to whichever sect or denomination is preaching doctrines that align with their personal beliefs (and bias and prejudices). It is almost as if they fail to see that such indoctrination has made them self-righteous Pharisees who use their religion to judge and condemn other people for living and making decisions that offend their sanctimonious religious sensibilities. It could also be that they are living in their own prison of fear as they are afraid of "displeasing" the idolised god of their imagination, and they are projecting that fear onto other people. 

On a similar note, here's sharing a short story "A Father, A Son, A Cigarette, And Jesus" by Mick Mooney, which does a good job to illustrate how some people in the Christian religion typically use guilt and shame to control and manipulate others to try to make them conform to their socio-religious norms.