The chapter aims to trace the presence of the concept of formless matter in patristic literature, focusing mainly on the exegetical writings devoted to the biblical book of Genesis by some of the most important Greek and Latin Christian thinkers who lived between the second and fourth centuries CE (Origen, Basil, Gregory of Nyssa, Ambrose, Augustine). The study is structured into two main parts. In the first part Moro analyses the theoretical arguments used by patristic thinkers to deny the existence of an evil material substratum, co-eternal with God; in the second part he examines how these thinkers appropriated and made use of the philosophical notion of matter, in order to demonstrate the functions and the theoretical status that it faced within the Christian doctrine of the creation out of nothing.