The ultimate right brain activity: going to church
When I was in college (>decade ago), I read some great research that gives me a context to understand this. I've been searching the web for articles, but it's surprisingly hard to finding articles on brain research that doesn't involve paying $19.99 for a CD, book, or "course."
I learned that here in the west, we live almost constantly in our left brain, the logical / language side: driving cars, grocery shopping, talking on the phone at work, etc. We, people here in general, rarely get a chance to use the right brain, the home of the artistic and emotional side of things. According to said misplaced article, hyper-left-focused Westerners should be on the lookout for activating those elusive right brain waves by doing things like burning incense & meditating, or maybe watching TV. (Because of this research, I did t'ai chi for many years and received many benefits from this "meditation in motion".)
It is the long waves in the right brain that make someone feel good & at peace.
In a completely different context, I leaned that when you hear the same exact words over and over, you don't "hear" it with your left brain any more, but your right. It becomes like a meditation, and scientists can measure the calming, long-wave brain activity.
Imagine one sitting in a religious service for the umpteenth time. Their brain long ago stopped interpreting the liturgy with the logical, "what is the meaning behind the words" side; instead the right side kicks in with what has become a meditation. Add to that the incense, music, beautiful windows, and surrounded by friends and you can see why someone would feel very calm and peaceful in this setting. And, as the link above about the TV mentions, at this state, they might be more receptive to ideas while in the throes of this right brain activity. Throw in a good speaker with an instinctive flair for emotional language, and suddenly you can grok how mega-churches have appeared.
I wish more people had this kind of information, because once it is understood, it loses its power of subconscious control.
After reading many articles, I suspect some people, stanch church-goers that won't examine their beliefs in the light of reason, can't imagine a life without what might be their only right-brain wave activity that they have.