"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." - Manuel II Palelologus
This has happened before: the Albigensian madness in southern France in the 12th and 13th Century. This was a gnostic religious movement which held that the physical world was evil and created by Satan.
They said the worst crime was to cruelly trap another soul in flesh by bringing another child into the world. Their main commandment was to abstain from natural (procreative) intercourse.
Their leaders, called Cathari, were celibate and morbidly ascetical: they wouldnt eat meat or burn a fire to keep warm (small carbon footprint?) -—and they condemned the Catholics who said it was morally OK to eat and drink and keep warm and marry and make love and have children.
The Albigensians told their followers that Christianity (Catholicism) was a lie and that they had no religious or moral obligations other than childlessness. It was OK for them to have non-procreativesex , so homosexuality and contraception were virtuous.
The Catholic Church was appalled by the rapid spread of this insane movement across southern France. After the failure of peaceful attempts at conversion, the Church was able to defeat them only by calling a Crusade.
Whats next with the New Albigensians? Watch and see.