The likelihood of effectiveness or plausibility of influence is a crucial condition for the obligation of "commanding to the famous and prohibiting from the infamous". This matter has long been a subject of debate among Islamic scholars in the fields of theology and jurisprudence. Some scholars condition the obligation of this duty on the likelihood of effectiveness, while others maintain that the obligation is absolute. Although the narrations cited to support this condition are subject to disputes regarding both their chain of transmission and their semantic implications, most discourse has centered on these narrations, while independent and rigorous examinations of Quranic evidence have been sporadic and superficial. Consequently, this study seeks to address the issue by examining the Quranic evidence invoked by both groups. Employing a library-based research method and an analytical approach, the study investigates what the Quranic evidence implies regarding the necessity—or lack thereof—of the condition of effectiveness. The findings indicate that the Quranic arguments advanced by those who reject this condition not only fail to negate it but, in some instances, actually reinforce the requirement of effectiveness; furthermore, the view that effectiveness is a necessary condition is substantiated by the principle of purposiveness in Divine actions. Ultimately, the study concludes that the Quranic arguments of those who deny the condition are flawed, and the requirement of the likelihood of effectiveness is established through the principle of purposiveness in Divine actions.