First of all, it should be clear that after reading the Glorious Qur’an, there is no act of worship better than dhikr and du`a’. The merits of dhikr are highlighted in the following Qur’anic verses: “Then do ye remember Me; I will remember you. Be grateful to Me, and reject not Faith.” (Al-Baqarah: 152)
“… and for men and women who engage much in Allah’s praise, for them has Allah prepared forgiveness and great reward.” (Al-Ahzab: 35)
Also, the Prophet (peace and blessings be upon him) said: “Surely, Allah, Glorified and Exalted be He, says, ‘I will be with My servant as long as he makes mention of Me and moves his lips in making mention of Me.’” (Reported by Al-Bukhari). “No people assemble to remember Allah but angels surround them, mercy covers them, sakinah (calmness) descends upon them, and Allah mentions them in His assembly.” (Reported by Muslim)
Although making dhikr in a group remains a question that needs to be answered, following is the Fatwa of the European Council for Fatwa and Research, headed by the prominent Muslim scholar Sheikh Yusuf Al-Qaradawi:
“Making dhikr in a group is allowed as long as the following conditions are met:
1- The dhikr is free from munkar or acts that violate the decorum of a Muslim, such as shouting and the singing of love songs.
2- The dhikr must not be done except with the known words mentioned in Shari`ah, and not unintelligible words or sounds.”