I have seen people going to certain gurus or temples, and they are mostly happier. The grounding factors are mainly psychological. When you go there, people tell you that if you visit that guru or that temple, your problems will get solved. This creates a psychological effect. You start believing that things will get cured, and naturally, your mind shifts into a positive mode. That belief itself gives relief. This is the first reason.
The second reason is that many spiritual gurus have their own processes — pranayamas, meditation techniques, rituals, and various practices. They form their own system and make their followers do it consistently. These practices keep people focused, occupied, and disciplined. When someone becomes fully engaged in these routines, there is no time to worry or overthink. Their mind remains occupied, and that itself brings a sense of happiness.
I am not trying to find faults with their techniques or the pranayamas they teach. Some of these practices may be scientifically proven; some may not be. That is not the point. The grounding factor is that these methods help people stay focused, and they also make them believe that their problems will get cured. This belief is powerful. Even when people go to temples, the same psychological effect happens. They feel assured that things will improve, which creates positivity. When they start praying or performing rituals, they become occupied and focused. This combination of focus, occupation, and belief naturally makes them feel better.
All these are the grounding factors — the major reasons why people connected to gurus or temples often appear happier. Whether it is a spiritual guru or a temple visit, the common result is the same: people become focused, occupied, and psychologically assured that their problems will be solved. This makes them happier.
That is why I have seen that people who are focused and occupied are generally much happier, even if they do not go to temples or follow any guru. Their happiness comes from being engaged and mentally steady. Focus and occupation themselves bring peace.