In contrast to Mr. Rochester, St. John Rivers is a very reserved, austere, albeit handsome, young man.  He is cerebral rather than passionate; his sermons and prayers have the austerity and sanctimony of the Calvinist in them.  With much self-righteousness, St. John holds his "evening reading" as he seeks to frighten Jane with his choice of Bible verses as prayers for her soul:

...all his energy gathered, all his stern zeal woke: he was in deep earnest, wrestling with God, and resolved on a conquest. He supplicated strength for the weak-hearted; guidance for wanderers from the fold: a return, even at the eleventh hour, for those whom the temptations of the world and the flesh were luring from the narrow path.

While Jane relates that his words "thrilled me strangely," as he eyes her. When she takes leave of him, St. John admonishes her to "remember the fate of Dives," the wealthy man who had to spend eternity in hell.  And, despite Jane's being affected by his zeal and asking him to show her the path, she experiences an inexpressible feeling; it is one of intuition.  That is, she feels throughout her body the call of Edward Fairfax Rochester calling to her.  With this experience that Jane describes as a work of nature, she rushes to her chamber where she drops to her knees in supplication, uttering prayers from the depths of her soul.  Jane has a metaphysical experience of "a Mighty Spirit" and she feels her emotions and soul rushing to thank God; her prayers are no sermon as are St. John's.  At peace, Jane rises from her knees and lies down, eager for the daylight in which she can begin her search for one who shares her passions.