This is the OP, highly encouraged to read so you guys get the full context
I don't believe ThatFanficGuy meant that people were ignorant and misguided. I believe he means that we are more efficient if organized (like cattle). It is easier to control a group of people so that they can survive than to let them all do their own thing.
From what I understand, religion started around 10,000 BCE, right after the development of Agriculture. As villages formed, people needed a leader to guide them so that they can organize efficiently to survive and harvest crops, while fending off danger. Law (through religion) was created to keep order, and myths were created to explain how the world around the people worked. As ThatFanficGuy said,
|Some people also enjoy abusing the power a religion often grants. Thus, come priests (who, let's face it, aren't always the benevolent wisemen we see in fiction); thus, come bishops; thus, comes Pope and other such figures - the "representatives of God on Earth", those who can "hear God's will" and so forth. If a lightning strikes a tree and everyone's terrified, it's the easiest of opportunities to seize their attention and wield their minds: come forth and declare "Lo! The All-Capable One spoke to me! He declared us wrong-doers! We must now repent! Chastize, brothers and sisters!". Case solved; flock organized.
Lastly, keep in mind how religion often circumvents attempts at logical explanation. I'm now going to overly simplify human nature for the sake of an example. Those affected deeply by the religious outlook (God made things, God takes things, I am a servant of His, I shall earn for good and be punished for bad etc.) will hardly if ever admit that there's often a more logical, reasonable explanation to whatever happened.
This abuse of religion to gain power ensured the leaders who were keeping the villages organized a luxurious life. It may have also been used to convince people they invaded and captured in other villages, as kingdoms and empires formed. Religious significance = Power back in the day, as seen in Mesopotamia and Egypt.
Half of the Religion wiki page is Modern issues, Reference section, and a very brief explanation of the very major religions. The main part of what Religion is and how it works can be summarized in say, the 1/3 of the article. It is true that religion benefited older civilzations when it came to survival, however I have say I believe it was the power of controlling people that religion brought together people under one ruler (the village/kingdom/empire leader). Divine Right of Kings.
I believe your point on group identity also falls under the above, like nationalism, even though they are being controlled by a leader, they get the feeling that they are special and are an important part of their society as they are taught so.