"Everything is possible for one who believes"

This article presents a homily by Cyrille Argenti devoted to the Gospel account of the healing of the epileptic child according to Mark (Mk 9:17-29), whose title takes up the words of Christ addressed to the child's father. The approach is homiletical: the text constitutes a sermon developed from a New Testament pericope. The central idea concerns faith as the condition and dynamic of healing, as it manifests itself in the confrontation between the powerlessness of the disciples, the distress of the father, and the omnipotence of Christ. On the theological level, the homily explores the relationship between faith, prayer, and divine action, drawing on the Orthodox exegetical tradition. It thus offers a testimony to contemporary French-language Orthodox homiletical practice, articulating scriptural reading and catechetical transmission within the ecclesial community.