Do not impose strictness on yourselves so that strictness will be imposed on you
The Messenger of Allah (may the peace and blessings of Allah be upon him) used to say: Do not impose strictness on yourselves so that strictness will be imposed on you, for people have imposed strictness on themselves and Allah imposed strictness on them. Their survivors are to be found in cells and monasteries. (Then he quoted:) "Monasticism, they invented it; we did not prescribe it for them."
Intolerance in religion is more dangerous than negligence, or say: both negligence and excessiveness stand against moderation, which is to observe fairness in all the matters.
Unnecessary strictness entails unjustified cruelty, and eliminating the characteristics of Islam, which has been previously mentioned, which is easiness, removing the hardship and the fewness of the obligations.
Imposing strictness on people is a sort of injustice and aggression against them, and a violation of the balance of justice, which this religion confirmed in all of its legislations.
The types of extremism are not countable, despite this fact all of them fall under two origins:
The first is the exaggeration in religion in order to exaggerate in worship. This is all evil and an innovation that is denied by the heavenly laws in general, and the law of Islam in particular.
The second is that the fabricated cruelty leads to the contradictions of the Islamic instructions.