Zikrullah or remembrance of Allah Taala is probably the most widespread and significant part of every worship. Generally, regarding Zikr, people think of doing some tasbeeh randomly or on a regular basis after Salat. However, the term Zikr is quite broad in meaning. Although tasbeeh, i.e. uttering ‘SubhanAllah’ is of course a Zikr, but Zikr is the remembrance of Allah in any prescribed form according to the Quran and Sunnah. For instance, if a servant encounters a sinful act, and immediately s/he remembers Allah and refrains from the sin in fear of Allah — this is a highly praiseworthy means of Zikr. Likewise, in Salat there is Zikr through recitations, invocations, and supplications. In Hajj there is Zikr as well. Even when the Muslims fight against the enemies of Islam, Allah Taala has commanded the Muslims to do Zikr abundantly. Similarly, every good action bears the Zikr of Allah. [See: Holy Quran 8: 45]
Indeed, without the Zikr of Allah, worship is nothing but an empty act embodied with worthless thoughts. It is the Zikr of Allah that lightens up our hearts with divine blessings. It is the Zikr of Allah that provides us spiritual strength. It is through Zikr the thoughts of our mind and actions of our limbs become upright. We become eligible for Allah’s blessings only when the Zikr of Allah takes place. Otherwise, worship is only a valueless display or artificial movement — there is nothing good in it — neither in this world nor in the afterlife.
Zikr is the action which Allah Taala commands the believers to carry on abundantly [See: Holy Quran 33: 41]. There is no other Ibadat for which such command has been given. For instance, it has not been commanded to say Salat abundantly, or say Hajj abundantly. Moreover, Zikr is a major condition attached to every worship’s accomplishment. About the Munafiqs (hyporats), the Holy Quran says that they do very little Zikr of Allah while performing Salat [See: Holy Quran 4: 142]. Therefore, one of the signs of the Munafiqs is that their Salat lacks the remembrance of Allah. On one hand, Salat is the most precious form of worship and on the other hand, Zikr is its major part — without the Zikr of Allah Salat becomes only an act of gesture and posture, which has absolutely no value in the court of Allah.