I suspect most individuals are protecting the idea, and most institutions, along with those individuals benefiting from the inner circle activities, are protecting the power.

Both. As Erich Fromm points out people turn to religion of get away from a sense of ignorance and powerlessness, perceptions that are very painful and threatening. Once in, they enjoy and exult in the sense of power hat is derived from being a member of a much larger body of "true believers."

I know several people on FB whose lives revolve around their participation in the church. Without the church, they'd lose their very identities. I think people with so much of themselves invested so personally in the church would do whatever they could to protect it.

Church is just a spiritual country club so that the “saved” can look down on the unsaved. I was guilty of it and if I’m honest I did look down on the unsaved. Now I look back and say it was bs

Religion acts like a tribal ID tag, provides comfort for people, "Relax, God is in control," although it is all fiction. Myths, like religious stories, and "Motherland" stories have enabled masses of people to organize and helped create the modern world, Yuval Noah Harari claims in his book "Sapiens, A Brief History of Humankind," for better, or worse, depending on one's perspective.
I know a couple of devoutly religious Christians who are really good people, and do not engage for any visible agenda. But, IMHO, there are many more for whom it is a power trip.

It’s probably best to pose this question to religious people instead of having non-believers conjecture endlessly.

Start up any organization and instantly people will flood in seeking ego-gratification, power and prestige through the control of others. It almost seems like innate human behavior.

That does not necessarily nullify the mission of the organization.

It is always those who have the greatest doubts about the value of their belief, or themselves, who make the biggest noise in its defense. Those who have no doubts and are genuine, have nothing to prove.

I'll have to agree, church membership, in many instances, has to do with the community/social status of the individuals. I've always thought that some attend church and see it as a kind of "country club" experience (without the golf course!). Various social gatherings are provided by many churches, i.e. garden parties, playing cards, recipe sharing, pot-luck suppers, chili suppers, and the list goes on. Are the activities wrong, of course not, but practiced in the name of the Lord and for his glory, I wonder. Larry in western Kentucky

Among the general population mainly answer A
Among the religious hierarchy almost exclusively answer B

I was told after leaving Mormonism (by three former Bishops) that almost everyone who becomes a bishop comes to the conclusion the church is not true very quickly, at which point they either leave (the rate of apostasy amongst ward and stake bishops is something like 80%) or they decided to make a career in the church by propagating the lie, these fuckers almost always move on to paid clergy work such as Stake president (with the appropriate honorarium or stipend) or move in to the CES (church education system) as a paid employee. (there is a myth that the LDS has no paid clergy, it is exactly that a myth.)
Once there you are on a career path that can and sometimes does go alway the way to being the Prophet when you are about 92 as a rule of thumb especially if you can find some spurious genealogical connection to one of the patriarch of the church, nepotism is a powerful force in all religious institutions especially the Saints.

I think people are protecting their idea of religion because without it they fear a lack of structure. Lack of adherence to the ten commandments. Mass murder, rape, theft and suicide. Hmmm... All of which seem to happen no matter what church you do or don't go to.
I dated a guy once who told me that if it wasn't for church he would not be a good person. He would drink and lie and cheat, maybe even something worse. We did not date long. The way I look at it, I don't lie and cheat. I drink wine with my friends but know my limit. Maybe I am just more evolved than him. And if that is what it takes for him to "be good", I guess, go to church. And if it makes you feel like a good Christian, judge me for not going. Seems counter productive but...

I think people go to church, believe in God, cling to their ideology because they are scared. Not because the want power (though that cannot be said for the leaders of the church). The truth is scary. You die and leave your family members to die without you. You don't see them again. So love them now. Show them that you love them now. Do good, kind things because you want to not because a book told you to. How about doing that instead of living a life of constant fear and trying to convert non-religious folks to "find the lord".
There are days where I wish Rapture was a thing. wherever they go they can preach to each other and leave me alone.

"God" is a modern invention.

Before man had a concept of intelligence or learned how to use it to conquer the beasts, he feared them. He thought of them as his mental equal and physical superior. Primitive religions worshiped them.

It's also natural to ascribe agenticity (conscious intent) to rustling leaves and burbling brooks, and we have natural animistic religions (pixies, sprites, etc,)

As man got a better sense of his place in scheme of things, his gods morphed first to half-human, half-beast gods (the minotaur, the Egyptian pantheon), then to human-like pantheons (the Greeks, Romans, and Vikings), and finally, to monotheism.

The all-powerful, all-knowing, angry, judgmental and dictatorial god - Yahweh - was the invention kings and priests that could then claim to be in communion with such a god - "God" to you - who they told us anointed them and then commanded others through them.

This was a hugely successful ploy for both the king, whose word and authority became as absolute, transcendent, and unquestionable as the gods, and for the priests, who were then able to live lives of relative leisure and elevated social status, as others kissed their hands and worked so that they wouldn't have to.

Organized religion and monotheism are political inventions, not natural.

"Man will never be free until the last king is strangled with the entrails of the last priest." -Diderot

This has been coming undone since the Enlightenment (Diderot was an Enlightenment philosopher), especially with the invention of secular government and church state separation, a huge blow to the church, and the source of an intense, revisionist propaganda campaign being waged in America as we speak. Neo-paganism, deism, and atheism are further threats to that power structure, as is independent theism ("I don't have a religion or a church, I'm just spiritual" ).

Isn't that obvious? That's why the biblical government structure is authoritarian and dictatorial, and why its ethical system is all about commandments, submission, obedience, turning the other cheek, meekness, and deferring your reward until after death, a reward you will lose if you don't comply. Noncompliance is described in words like rebellion, blasphemy, impiety, unrighteousness, trying to escape accountability, being demon filled, hatred of a good and just god, the moral turpitude of atheism, and elevating yourself to godlike status.

It's really pretty obvious when it's all laid out for you - unless you're wearing the Jesus goggles.

It's politicized monotheism, which is what is implied by the use of the term "God." Personally, I think we all(atheists) should consider abandoning that word unless it is your purpose to facilitate the preservation of that politicized system - or to drive that system into contrast as to what it represents and eliminate it.

Yes.

A great question. The realist that I'm, I'm known for approaching the issue/ problem starting by its roots. I have my share of research in the field of the reasons and circumstances that drives/drove people to claim/belief to be that they are 'god' s messangers' and the reason why they or their followers want to let that 'need' rest on.
The question that you are asking could be examined by the origin of the certain belief you are trying to examin itself.
Take the so called 'Christianity' for example, (I used 'so called' cause there are enough scholars who dismiss the idea itself of Joseph's son, Jesus, to even been crucified!) There are historians who report the fact that in the time of 'Jesus' the idea of a 'messiah' or being one was so 'Trending' that the numbers of self proclaimed 'messiah' s' are estonishing! So did Jesus do that cause he enjoyed the 'fame'? Was he just in love with the idea cause others 'Liked' it the way you feel forced by social media corporates to 'Like and Dislike' stuff 24/7? Did that get him killed? Is the story of the nowadays known Jesus a gathering of the stories of all his fellows JesuseS?
So did he do it fo power, for fame or just cause it was trendy? The same goes btw for Muhammed who describes in his own Quran how the 'words of god' were transferred to him during the 'moment of revelation'! He reports seeing a great shining light in parts of his vision, then tarts to shake so heavily that his a great noise is easy to hear from his jaws clapping theeth! If you dive deeper into his 'revelation moments' you will see an exact diagnosis of what he said/thought to be a 'god' s revelation' as a specific form of epilepsy called TLE. He is also reported to be an orphan, his own mother didn't apparently even want him cause even Muslim scholars tell you that she sent him directly after birth to live for at least 2 years with a completely different tribe! O yea, they claim she did it so he "can learn correct Arabic"!! Her husband, his proclaimed father, dies before his birth and she has no others in her life so she gives away the only thing that could give her a sense of family! So looking at his story and the many obstacles he had to endure you can probably assume that he wanted to gain power and with that came money and ofcource never forget the chicks, the women! All the so called 'nice' Quran verses are known to be 'Mekkiah', meaning it was revealed to Muhammed when he was sieged for ten years by his own people of Mekka for distoring their daily life with his 'revelations' so in that weak position he only had 'peace and love' to show! But when he and his friends had the upper hand in the 'Medina city' you started seeing verses such as "kill the nonbelievers wherever they are" and among those and others you'll find at least 86 verses you can bundle as a handbook for buying and selling (underaged) girls/women(slaves)! In the case of Muhammad which might be different than Jesus's you see thurst for power and revenge!
If you compare as much history sources as you can you will probably get an idea on why religion starts at the first place and why the followers (which are mostly not the religion itself) want to keep it or enforce it for their own personal gain!

Religion: to the ignorant, true; to the educated, false; to the rulers, useful ~

Strangely enough... I live in a neighborhood that is almost 100% Catholic... Super nice people. We never discuss religion as I am sure they have heard through the grapevine I am not religious and it is obvious to all they are.

I am unaware (from looking at them) that they are in it for anything other than to have someone else in control (less power there actually!) or they want to make sure they go to Heaven.

There was a time I thought about starting my own church but only as a money making endeavor. There are A LOT of suckers in the US... Just look at Trump's base!

"Do you know true believers that would spread religion even if it does not bring at least some apparent advantage?"

Rewards come in many forms. There is always an advantage, if not in this life, the one they believe is yet to come.

I have an uncle that became a Baptist preacher because he thought there was money to be made.

He's no longer a practicing preacher.

As for your question; I believe it's all of the above.

Power and money is what is most important or the pastor would not need a new jet to get closer “talking “ to god.

Both

Any religion is a source of immense power to those who purvey it, a representative of ANY religion can gain almost immediate access to the Political Leaders of a country or a Nation simply because they can claim to represent this God or that God, etc.
A vast number of the Faithfools spread religion under thecguise of doing their 'God's' work and that also gives them a sense of being powerful and having a higher social standing over those who don't fit neatly in to their 'special' little clique.
Imho, the ONLY advantage, if it could even called an 'advantage,' that religion offers is somewhat akin to what a sheep feels when it is surround by the rest of the flock, i.e. it feels safe from the 'prowling wolf' that is Reality.

To try to answer your question: Do you know true believers that would spread religion even if it does not bring at least some apparent advantage?

Religion... pure and faultless is this: to help widows and orphans in need and avoiding worldly corruption. James 1:27

What is wrong with spreading true religion of helping widows and orphans in need while avoiding worldly corruption?

And, how would it not be advantageous to avoid worldly corruption?

If you are refering to any thing other that helping widows and orphans, etc. as being religious, why do you call such activities a religion?

I have long thought that Stalin wasn't atheist, he just wanted to ensure religion had no power.

When you have nothing else, they seek spirituality which becomes organized religion since most do not have any real imagination they become the masses who do not doubt that the mystical magical being(s) which dominate their very being which over sees their very being as they virtually interpret it’s plan!!!

LOL!!!!