"Sangat" is congregation. "Sadh" is saint. "Sat" is true.
All these three words refer to a gathering of, or a meeting with, God-oriented people. The group may come together to say prayers to God, sing kirtan, listen to kathas or discuss spirituality and religious matters. They may meet in a Gurdwara, the Sikh place of worship, or at home, or anywhere else.
Most commonly, a sangat gather in the presence of the Guru Granth Sahib - the Sikh holy book. Wherever people gather to sing the praise of the Lord, or to talk about Him, they are referred to as "Sat Sangat" or "Sadh Sangat" – "holy gathering". While the word Sangat can refer to any gathering, but within the field of a religious faith, it refers to a true, wise or holy gathering.
Man is known by the company (or sangat) that he keeps. Man is the result of his environment. Bhagat Kabir says: "ਜੋ ਜੈਸੀ ਸੰਗਤਿ ਮਿਲੈ ਸੋ ਤੈਸੋ ਫਲੁ ਖਾਇ ॥ Jo jaisī sangaṯ milai so ṯaiso fal kẖā▫e. According to the company one keeps, so are the fruits that one eats" (SGGS p 1369).
So the company that one keeps is a great force and it plays a big role in shaping the person. Those who live in the company of thieves, robbers and evil persons, acquire evil ways of life and are bound to become thieves, robbers and the like, but those who keep the company of saintly people are shaped in the saintly mould and destined to follow the path of spirituality. .....More