I think lots of people spend millions of hours and countless words trying to explain religious belief and adherence to the belief.
I think every single aspect of religion can be explained in one very simple concept: ingrouping
Ingrouping is defined as an exclusive, typically small, group of people with a shared interest or identity. And once someone becomes a member of a group, and they take on that identity, it can cause a whole lot of change in their thinking. Such as (source: Wikipedia)
Ingroup favoritism. When part of a group, and identifying with a group, individuals tend to see the group interests and other members of the group as more important, or worthy, or notable.
Outgroup derogation. People and ideas not in the group, as a result of ingroup favoritism, are seen as less important, less worthy, or less notable.
Social influence. People will adjust their preferences and beliefs more in-line with the group.
Group polarization. As a group, people may make statements more extreme than if made by themselves. If a group’s beliefs are to the sides of a normal bell curve, within that group a new center is established. Individuals are therefore able to make more radical pronouncements without falling outside acceptable group limits.
Group homogeneity. This works two ways. Positive differences are celebrated within the group, while outgroups are seen as all similarly uninteresting. On the other hand, outgroups may be seen as full of problems, while the ingroup members see themselves as similar in their stance on the issue.
Certainly, ingrouping can be a positive characteristic. Groups that work together tend to thrive, and they work together best if the individuals feel like part of the team.
On the other hand, it is also easy to see the negative effects of ingrouping. Favoritism can lead to poor decision making. Social influence can become a sort of mind control or brainwashing. Group polarization disregards the reasonable and prefers the radical. And outgroup individuals can suffer at the hands of the in group.
Religion is simply an ingroup, with a laundry list of beliefs. Left to their own devices, no reasonable person in the 21st century would believe that symbolically eating a 2000 year old Jewish zombie was the way to bring peace and happiness to the world. Yet get someone in the group early or long enough, and they may consider this a proposition worth building their life around.
No sane human in the 21st century would assume that there are some things for which you have to just be gullible and accept. No sane modern human would fault you for not believing in something until you checked it out first. But get someone in the group early or long enough, and their gullibility is lauded while simple questioning is scorned.
No intelligent person in the modern western world would assume that hurting another human being for being who they are is a good thing. But if introduced early or long enough in religion, and these same people will vote and act to degrade, strip rights, and oppress people that are seen as different.
Oddly enough, many religious people in recent decades suggest that their religion is not a religion, but a personal relationship or experience. And to a certain degree we see the effects of this mindset- increasing percentages of atheists. Outside the group, without the group think and outgroup hostility, many religious people begin to lose their religion.
Naturally, the churches also see this trend, and rally against the idea of religion by yourself. Church attendance and adherence to the bullshit the preacher spews are required, or heavily suggested. They know, even if they don’t know why, that staying in the group keeps the individuals locked in the ingroup mentality.
Now, not all groups are bad. As I stated earlier, groups are capable of amazing productivity and effort. But we don’t judge a group by how hard they work, we judge it on the outcomes.
Covering up child rape is a bad thing. Religious ingrouping makes it possible.
Denying lifesaving medical attention is bad. Religious ingrouping makes it possible
Denying happiness and equality is bad. Religious ingrouping makes it possible.
Making public policies that suppress people and keep them poor is a bad thing. Religious ingrouping makes it possible.
And here is the punchline: Every single person in the world that calls themselves “Christian” allows all these horrible things to happen BECAUSE without their participation, the ingroup dynamic would fall apart. Every single Christian provides the group with the security and mental real estate it needs to fight for bigotry, hatred, and scientifically illiterate policies.
Think for yourselves, people.
The Spartan Atheist