What makes a religious text authoritative? In what does ‘authoritativeness’ consist, and how does it change? How are relations between Muslims and authoritative texts reimagined and reconstructed? This paper explores these questions by focusing on a recent debate in Turkey around the notion of ‘Kuran müslümanlığı’ (Quranic Muslimhood). Turkey has a long lineage of calls for a ‘return to the Quran’ (against, for example, ‘superstition’ or Sufi ideas) since the late Ottoman period; the current advocacy of ‘Kuran müslümanlığı’, however, departs from earlier discourses not only as a popular movement cohering around a broad coalition of Muslim groups and individuals, but also by aiming to establish the Quranic text as the exclusive authority on Islamic practices, from prayers to marriage. Many recent anthropological studies invoke the idea of ‘discursive tradition’ to highlight that authoritative texts (e.g., the Quran, hadith) are effective sources of articulating Muslim subjectivities in the present. Others, however, have suggested that this perspective limits its scope to the ‘puritanical’ orientations underlying contemporary revivalism’s argumentative style (thereby dismissing, for instance, dreaming as a mode of knowledge), or that it attempts to impose coherence on disparate manifestations. While these debates have been useful in highlighting contestations around the place and interpretation of authoritative texts in Muslim communities, this paper instead considers what is involved in Muslims’ relationship (or lack thereof) to specific texts. I focus, in particular, on how ‘Kuran müslümanlığı’ comes to be organized not simply around a textualist effort to reinstate the hierarchical status of the Quran, but also through its promotion of ‘evidence-seeking’ as a God-sanctioned obligation (farz). In my discussion of this reinvigorated and popularized interest in evidence (delil) concerning the shape or content of practices (e.g., daily prayer movements, fasting times, or hajj rituals), I first demonstrate how evidence-seeking becomes a fundamental component of the practices for which evidence is being sought. Second, I highlight that this discourse of evidence has generalized a traditional notion of religious doubt concerning 'probable evidence' from non-Quranic sources, while opening up a space for modern notions of certitude (e.g., knowledge unaltered by personal mediation or a privileging of written over orally transmitted sources).