Regardless of what religion you believe in, I think it is important to understand the theory of collective effervescence, or the power of the masses.
The theory basically entails the idea that long ago when there weren't that many humans on the earth, we were hunters and gatherers. To search for food efficiently, it made more sense to split up so they could cover more ground. Yet, this didn't make it that much easier for them. They spent most of the days on their own with little to no sense of community.
Think about a person's every day life; you experience a community when you go to class, when you walk into a Starbucks, or when you go to church. In the very beginning, there weren't Starbucks at every corner, nor were there 3 churches in the same town(or in the same region for that matter).
Moreover, when the hunters returned, there were celebrations, feasts, and rituals. After spending so much time alone, just imagine the uplifting feeling that community would bring: excitement, love, agreement; it must have been very intoxicating. In modern day terms, think of when you go to a huge football game or a party. It's not the actual game being played that makes it worth going, or the house that people consume at the party. It's the people that consume these places, it's people that give the events meaning. Imagine if you went to the Superbowl and you were the only one in the entire crowd- wouldn't be as fun , right?
Since these celebrations weren't very frequent, it is likely certain aspects became associated with these celebrations, and in turn, became sacred. If deer were always present during these celebrations, the symbol of a deer eventually became sacred, as it represented the joy experienced through the celebratory gatherings. This expanded into other symbols like the stars, and different Gods, etc. Eventually this process repeated itself so many times that these sacred symbols became accepted as the norm- they were sacred just because they were.
Durkheim thinks that religion was actually mistaken for this concept of collective effervescence. Regardless if this is true, it is important to take away that the power of the collective can dictate one's entire life, as seen in modern day experiences. People's behavior is impacted by social norms and by what "just is." Good advertising influences what they think "just is."