Why does Julien Sorel choose the church as a path to success?

In Stendhal's novel The Red and the Black, the protagonist Julien Sorel chooses the church as a path to success primarily because the military, which he initially viewed as a viable route for advancement, was no longer a realistic option following the fall of Napoleon.

As an intelligent and sensitive young man, Sorel is driven by ambition and a desire to make his mark on society. Finding his path to military glory blocked, he turns to the church—symbolized by the color black in the novel's title—as a pragmatic alternative for career advancement in the climate of Restoration France. Sorel views himself as an unsentimental opportunist, and he pursues this ecclesiastical path as a calculated strategy to overcome his social standing and achieve the success he craves.1