Rules of God or Rules of Man?

The saying, "Religion is the Opium of the masses" is attributed to Karl Marx but that only forms part of his thinking.

All religions have rules that are created and administered by man.

Man as we all know is a weak creature and prone to sin and deceit and throughout history religious authorities have made the rules to wield as much power over their followers as possible and that includes some Popes and other religious leaders.

In medieval times it was important for people of the same religion to know that everyone was being faithful to the rules as otherwise entire cities could be under threat.

For example if one turned against his religion and converted to say Islam from Christianity, that person could poison the water in the well or open the gates to the city.
I think the punishment for apostacy probably arose from such historical reasons.
Also pigs being considered haram probably arose from health reasons as in the old days infections were not easy to control.

My basic take is that scholars can quote from whatever authority but the basic reason is that top leaders want to wield control over the reason of men.

If followers do not think it make life so much easier for the leaders. The only question is, "Is not mankind different from the animals by his ability to think?"