Satsang, meaning “companionship of the righteous,” is emphasized for spiritual aspirants of all levels....What is so important about worshipping together or interacting with other people who share the same interest in spirituality? First of all, it teaches us to connect to each other and to God in place of connecting to God alone. Connecting with each other for a righteous cause is an important lesson to be learned in life, for it gives us a foresight in dharma at a collective plane. Without this initial lesson, we may never develop the impressions for tolerance, peace, and “seeing God everywhere,” cultivation of which is compulsory for becoming a great soul. Satsang teaches us to keep our ego in check, for it promotes sharing of God’s love and prevents us from ignoring fellow humans under the excuse of spiritual evolution. It opens the gates for exchanging good wishes and blessings with fellow beings. In addition to making us more spiritual, satsang develops the wish to live with ethically gifted people. Thus, in the long run, this translates to an eternal wish of making our community a better place to live.
In a more traditional sense, satsang refers to the company of saints, who have God in their heart and continuously aspire for him.* It is believed that they can radiate positive or spiritual energy to our minds, and their presence can accelerate our spiritual progress, just like the company of the immoral can trigger our tamas instincts.
Excerpted from Devotional Hinduism by M.S. Goel (2008), p. 20.
*Note that satsang is a much wider term than listening to discourses (pravachan), though the two are often used as synonyms today.