“The company of the great is very difficult, even inaccessible, but it is infallible.” (Narada Bhakti Sutras. 39)
Literally speaking, “sat” means truth, and “sang” means to be associated with. Satsang in Hinduism usually refers to a gathering of spiritual aspirants, and participating is such gatherings is meant to lead to tremendously greater progress than spiritual practices performed solely alone. The concept of satsang can equally apply to other endeavours in life.
All but the very best amongst us are profoundly influenced by the people who we spend a lot of time with; for better or for worse.
When attempting to achieve something which involves obstacles, be it worldly goals or inner development, it helps tremendously to have the company of people who are trying to achieve something similar, or better still, the company of people who have succeeded in achieving what we are trying to get started on.
I found out the hard way that many high aims and ideals which I tried to apply to my life were very difficult to maintain without arduous and tiresome struggle, compared with when I used to be around people who were involved in similar endeavours or had a similar mindset.
That is the reason why religious communities of some sort or another are very important for most people who are following a religious path. Alone, just left with books and perhaps other forms of media such as videos and magazines, it is very difficult for most people to imbibe and live out our aims and ideals. It could very well be that some exceptional persons amongst us could achieve their potential without the company of like-minded people or an inspired peer group, but such people are quite rare, and even for such individuals there will have been a period in the formative period of their character, where positive influences of others will have been exerted.
The principal of satsang applies equally to worldly (outward) endeavours as with spiritual (inward) endeavour. An examples; one observes many floundering Hindu activists who appear not able to leave a dent on the challenges and predicaments facing their cause; the survival of Hinduism and Hindu society. Many such individuals have learnt about the problems in fair detail and are armed with knowledge. However many are isolated and do not have the benefit of being around people who believe in or are trying to achieve something along the same lines.
It need not even be people who believe in exactly the same cause, but even the company of people who are dynamic, able and willing enough to achieve something for other causes will suffice to transmit energy and thereby reinvigorate the floundering with the energy to move mountains.