What is your opinion of the the book "The Forty Rules of Love"?

The book discusses a dangerous esoteric idea revolving around the doctrine of the unity of religions, the unity of existence, and divine love. Its events revolve around Rumi and Shams Tabrizi and their call for tolerance and divine love, and their rejection of external jihad. These ideas appear through the forty rules contained in the novel, including: that the Quran is understood on different levels, that God exists in the heart of every lover, that most problems stem from a misunderstanding of language, that God is busy completing the making of man towards perfection, that every human being is an open book, that Satan is an inner voice, that differences must be respected, that a person's heart is what matters, not their outward appearance, that time moves within us, that there are no adversaries or others, that nothing should come between man and God, that religion is the religion of love, and that life has no value without love.