This paper aims to explore the complex relationship between intellect, knowledge, and free will in the context of religious faith, īmān or fides. The paper focuses on the perspectives of two prominent theologians, Abū l-Muʿīn al-Nasafī (d. 508/1115) and Thomas Aquinas (d. 1274), from the Middle Ages. The study begins its investigation by looking into the aforementioned theologians’ ideas and interpretations related to the nature of religious faith. It then explores the specific roles assigned by al-Nasafī and Aquinas to intellect, assent, and free will in the act of faith. The article’s final section presents a comparative analysis of their perspectives, highlighting the similarities, differences, and potential tensions between their positions. The findings of this study suggest that Aquinas’ argument, which asserts that grounding faith in knowledge or evidence undermines human free will, may have certain problematic aspects. According to him, one necessarily assents to the proposition at hand if there is conclusive evidence. However, as for al-Nasafī, it appears that one can rely on evidence and exercise his/her free will in the act of faith if religious assent, taṣdīq or agnitio, is understood in a dual sense.