Madame de Stael's quote suggests that living a spiritual life is not always easy. It implies that it is a challenging journey, instead of a peaceful and harmonious one. This is likely due to the reality that spiritual life needs an individual to stick to specific beliefs and practices, which can be challenging to preserve. It also recommends that religious life is not constantly a pleasant experience, as it can involve battles and challenges. This might be due to the fact that religious life frequently includes making sacrifices and dealing with hard decisions. Eventually, Madame de Stael's quote implies that religious life is not constantly simple, which it needs commitment and perseverance in order to achieve success.
"Life is life - whether in a cat, or dog or man. There is no difference there between a cat or a man. The idea of difference is a human conception for man's own advantage"