We deal with religious figures in the work of Gustave Flaubert and the questions they ask, in particular those involving La Tentation de Saint Antoine with Bouvard and Pécuchet. This has led us to deal with the dialogue between religion and science through demonstrators and wise figures. The tragedy of belief and the anti-religious thinking they embody, each in their own way, will be reflected in the theological debates of the encyclopaedic novel. The science of the Diable, going back to the origins of Christianity, unveils the variety of religious forms and undermines its faith. Similarly, the two heroes of the last novel will call into question the Christian dogma and clerical authority by reading a modern exegesis manual, made up of knowledge that served as a critical part of the Diable. The priest figure, for its part, is a patchwork of religious received ideas that Flaubert has gleaned in the books of modern apologists. The ambiguity of saintness characterises the religious figures shared between the need to believe and the desire to know, mystic aspiration and sensuel love. The theme of desirability and saintness brings together La Tentation, Salammbo and the Three Kits. We discuss how the nineteenth century knowledge, including religious and scientific knowledge, has fuelled religious figures whose attitudes towards symbols tend to evacuate dogmatic content. Criticism of dogma is not a denial of religious enthusiasm, but a way to invent a poetic of plurality and to regain the religious sentiment behind all beliefs No summary in English