What is the ruling regarding someone who mocks religion to a religious girl by describing her as an extremist, and is it permissible to sit with those who mock religion or frequent them after they engage in other conversations, and is repeating the phrase "Mutawa' of Buraydah" to some religious people considered mockery?

A Muslim must change evil with his hand, tongue, or heart. Know that mocking religion and its people, and backbiting them, are severe evils that Allah has forbidden, as well as accompanying and befriending those who engage in them. One who enjoins against evil should treat people with gentleness and be kind in his call to them, and debate with them in the best manner. If they do not desist, then one must leave them, because whoever sits in a gathering of sin and does not condemn it is equally sinful with them. The listener does not absolve himself of the sin of backbiting unless he condemns it with his tongue or heart, or leaves the gathering. As for speaking about "Mutawwi' Buraydah," it is not considered mockery unless the speaker intends sarcasm and derision.