Currer Bell is trying to discourage readers from judging the book harshly because it challenged the status quo. When she says "Conventionality is not morality. Self-righteousness is not religion." She is saying that she people should not follow the opinions of the establishment because of it’s biases, but rather form an opinion based on it’s own artistic merit. She also uses an obscure biblical reference to show how the book is not anti religious but rather disagrees with select interpretations of Christian morality.