I don't think that Elsa outright dismisses faith and spirituality. I think she doesn't support the traditional Judeo-Christian view of faith and spirituality. Pastor Marius represents that belief in the story. Miss Helen has ceased attending church for many years now. She finds her own spirituality through her art and creative expression. Her entire house is devoted to manipulating light and mirrors in order to light her home and her soul. She has faith that her actions will lead her to her Mecca where she will find peace and safety from the darkness. Her end goal is relatively similar to what Marius wants for her, but the method is different. He believes that Christ is the only way for spiritual salvation. Miss Helen believes in her way.
Elsa supports Miss Helen. That doesn't mean she dismisses faith and spirituality. It simply means that she supports Miss Helen's decision to find her own spirituality through her creative outpourings. Elsa likely believes that there are multiple avenues to spiritual harmony, which is why she doesn't try to push Miss Helen back toward Christianity. Elsa sees that Miss Helen has peace and comfort from her own religion, and that's good enough for Elsa. That attitude reminds me of the book "The Life of Pi." In it, the main character is Muslim, Christian, and Hindu all at the same time. Pi took from each religion what he liked most in order to give him the most spiritual comfort. I see Miss Helen acting that way, and Elsa supporting it.