By Sri Skanda's Warrior of Light
Satsang refers to the fellowship of devotees who seek spiritual unfoldment by gathering to discuss Truth. This discussion of truth (which is synonymous with God) usually takes the form of sharing personal and divine experiences with the company of other like-minded sadhakas (a devotee doing sadhana or spiritual practice).
In the 7th century A.D., renowned Saivite saint, Thiru-Navukk-Arasar (aka Appar) sang the famous Namachivaaya Pathigam ("soTRuNai vEdhiyan..."). In this exquisite bakthi-impregnated decad is a beautiful stanza that alludes to the importance of Satsang:
In the seventh stanza, Appar swaamigal advises the sadhaka to seek out and be among the company of (in this case) Siva devotees. By so doing, Appar accounts that as soon as he sought the company of Siva's devotees, he had the darshan of God Siva and that Siva in return sought him (Appar)!
Appar eloquently tells us all that to develop and cultivate good qualities, the sadhaka should seek out and be among the company of like-minded people who are working to tranform their hearts and minds thus, continuing forward dynamically in their soul's evolution to realize and merge with God. This is the essential purpose of Satsang to derive the maximum spiritual benefit by engaging with others of like mind and spirit. To do so is a great blessing and one that we must take advantage of should we avail the opportunity.
The Saivite saint further hints that through satsang, other sadhanas such as Japam (mantra recitation with prayer beads) and Dhyaanam (meditation) yield quick and effective results because it helps the spiritual aspirant cultivate strong faith, good character, and noble qualities essential for progress on the spiritual path.