'The opium of the people"

There are two different questions here.

1. what was the purpose of the “founder” of the religion.
2. what are the purposes of the owners of the religion
   Then we might ask why do people chose to believe.

Religion was supposed to be an organized way to know god. The whole conformity thing was a way to keep people from being wild. Look at prisons, how they find Jesus and then become more moral. But religion CAN serve a good purpose, for people who lack organization in their lives. People aren't going to want to go to work and be a cog in the machine, if they know they are just putting a roof over their heads and it's not going to end. Being told if you suck it up while you're down here, you will be rewarded later, because God likes to see you suffer, was a way to keep the masses working for the elites.

I think the truest purpose - was convincing men to die willingly in warfare. The promise of a glorious afterlife was an effective incentive.

In a word, CONTROL

Emile Durkheim, the founder of sociology, famously said that religion was "society worshipping itself" symbolically. For him, religion existed to promote social solidarity, to keep the society together, and everyone on the same page. Karl Marx said that religion was the capitalists' way of distracting workers from their oppressed and overworked condition by promising that their reward would be in the afterlife. Economic anthropologist Marvin Harris feels religion is there to keep the local ecology and economy in line, and that "primitive" religious practices really serve other purposes. For example the Hindu prohibition on killing cows makes ecological sense because you can feed more people longer on the milk, butter, and cheese that a living cow produces than if you killed it and ate its meat. Those are the major social science perspectives on it. There are more, but I don't want to write a novel.

Seems religion is a way to control every aspect of a person's life.

What you describe is called philosophy.

Religion is merely supernatural philosophy.

It's just another way of exploiting the natural fear of the unknown. For the leaders own lust for power.

Simply put, religion is a business whose only purpose is provide employment for the clergy and support staff..

Were it not for the government sanctioned tax breaks I believe religion would go out of business very quickly.

In my opinion religious institutions should be taxed just like any other business.

Religion does not offer any meaningful education; religion is the perpetuation of a gross lie upon one's fellow human.

Control.

I would think it was originally just a way to explain nature. Then people saw how they can control others through it.

Religion was initially begun to teach people how to behave to each other. That very quickly accelerated into a way to control a large group of people.

I think there are too many varied reasons that people use religion or are used by it to explain simply.

and power...

Religion was invented when the first conman met the first fool.
Market Twain

No, the reason is that humans are afraid of dying

To control the masses.

Simple we don't need it

Religion is an industry that thrives on control of both thought and behavior. Once you've got them hooked with outrageous promises of eternal life and an all-powerful deity they'll come willingly to be lied to and pay substantial sums of of money to be reassured by those lies.

Religion is an evil, cancerous business kinda like tobacco but with magic.

Religious beliefs are born out of the Human fear of death. We all die. But no one is in a particular hurry to get there. And when we do, we hope that we will be 're-born' into whatever 'afterlife' our religion has taught us, exists.

To have a controlled life

I think religions are primarily the expression of the fight or flight instinct. At some point our ancestors' brains got big enough to grasp the concept of the future and that we will all eventually die. The instinct would have none of that so people came up with various ways to convince themselves that they will not die after they die. Obviously, that is not the only reason for religions but I think it is the main one. I read somewhere that out of the several thousand of religious beliefs only a few don't promise surviving death in one way or another. Other readons are the daddy in the sky that watches over you, the need for being to know what is right and what is wrong, the explanation of the unknown, ect.

The idea most likely started out good and religious groups today do do a lot of good things. Sadly they also exclude many who need the kindness of a group the most. They promote a like mindedness that is limiting and in the past this may have been needed to feed, house and clothe the family, life in the past WAS fucking hard!! With fear and lack of education religion controlled the masses, it exploited the masses. But they got everlasting life.
So how it is with modern farming, technology and medical advances religion is still so popular? I have no answers only more questions.

For some that may be partially the case. For most it's a fear of death and also dealing with the passing of people around them. I may have accepted death and eternal oblivion as a fact but that didn't mean I'm not afraid of it. Or rather the thought of it. Most are.

There also the aspect of justice when people are wronged, when a life is taken. Most want that person to have an absolute punishment. Something that goes beyond a jail cell or execution.

It also works to control others. Bend them to the desires of the elite. Keep the masses under control. Made their morals, ethics, and actions justified. Without religion and a god or gods backing them they have no other way to do so. Though the case for objective ethics can be made without the supernatural. Not one for fundamental ethics though, which is what religions attempt to do. Many people desire purpose or a place in the grand picture. Religion provides that to them. Though some also need a reason to not be cruel to another human or animal an religion provides that as well. The idiotic argument we've all heard "if there's no good then I could just go around killing people. There's no punishment and reason reason not to".

To add to the nuance it's also because of laziness. There's no need to attempt to explain nature, the how's and why's, life, death, morality. I think that's where the basis of most religions is located. Someone asked why, they didn't know. So they created a story that made sense to humans with the IQ of a goldfish.