The Ulema and Mashaikh say there are four types of Gatherings regarding the effects on ones spirituality:

1. Some are like Medicine; without these, one can not survive.

For example, a gathering for seeking earning through a halal job to provide for one's family. (So these should be limited to the extent that is necessary, because overdose of even a life-saving medicine is harmful.)

2. Some are like an illness; diseased.

These are the gatherings of duniya, of frivolous activities, where ghaflah (heedlessness) takes place. These could be gatherings of people, and sometimes, even useless browsing on the internet. So once you have made true Tauba, in order to safeguard it, you should avoid the majaalis of ghaflah.

3. Gatherings that serve as 'Poison'.

This is poisonous suhbat (company) - it can be in the form of haraam suhbat or 'Incompatible suhbat'.
As far as the haraam majlis goes, even if you claim you will not commit anything haram (unlawful) there, why do you wish to be seen at such a place anyway, where Allah's gaze of wrath and anger pours down?

Second is the suhbat of those whose values and aims are Incompatible with pious people (Na-jins). This means to keep the company of people who are not trying to earn the pleasure of Allah swt. Why? Because you do not know who is influencing who; So one should avoid the company of those who are not dyed in Sibghatullah (The Color of Allah).

4. Some gatherings are like 'Food' - food for the soul

Like food, these majaalis provide spiritual nourishment to one's Ruh. These are the gatherings of Ulema, Tulaaba (students), Mashaikh. One must attend such gatherings so that the Ruh is nourished"

-Notes from Shaykh Kamaluddin Ahmed's Talk on 'Leaving the Laghw'

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