Believers, whose traces are lost after the last documented exhibition, in 1920-21, is often cited in the writings of Morbelli and judged by the Alexandrian himself, a crucial passage in a pictorial process already undertaken in the early nineties of the nineteenth century in the direction of the new pointillist technique, experimented independently with rigor and audacity. The atmosphere of the entire composition lives on the mystery that emanates from the silhouettes of the devotees wrapped in the half-light, to suggest a sense of intimate and peaceful communion with the divine. The interior of the Milanese church of Santa Maria presso San Celso captured at sunset is flooded with white rays that burst from the windows - like lights that must have the maximum value - to warm the small dark crowd of the faithful against the light, some kneeling on the ground, some on the kneelers, each lost and at the same time understood in the majesty of a void that collects the orange glow of the half-open curtains to place it on the high walls and on the admirable floor, which surprisingly reveals the beautiful decorative texture. The reasons for a chiaroscuro of powerful visual impact prevail in the work, obtained by illuminating the "dark masses" with the "veiling and splitting" of color through alternating plays of contrasts and assonances until the desired effects are achieved.