What is the ruling on the phenomenon of “Modernism” and those who affiliate with it?

Question:
A questioner says: We have heard of a fatwa of yours regarding “Modernism,” so we ask you to present your position on Modernism, and what our position should be toward the people of Modernism? May Allah reward you with good.

Answer:
We have read about them ugly and abominable writings. Our brother, Awadh ibn Muhammad al-Qarni, composed a treatise on this, in which he gathered a group of them and quoted some of their words, as well as the newspapers that mentioned it. Based on what has appeared to me of their condition, according to what I have read of their words: they are atheists who call to corruption, and call to rejecting the Shari'ah. They achieve this through vague, obscure expressions that people do not understand, and their aim and goal is to reject the old and not submit to the old. This means what the Messenger of Allah (peace and blessings be upon him) brought, meaning: fighting everything old and supporting the new. This means they fight the prayer, they fight Islam, and they fight everything old. They have ugly statements that I have read about them.
So whoever is of this description, there is no doubt that it is obligatory to boycott him, disavow him, warn against him, and call him to repent to Allah. As for if they have some things other than this that are few and we do not know them, that is another matter.
The point is that what I read about them, and what our brother, the Shaykh Awadh, mentioned in his book, is that the evil of these people is great. It is obligatory to be cautious of them. They are an innovation that must be removed. They called themselves “Modernists,” and they are an innovation that must be removed. They must be dealt with. Whoever is known among them is called to repent. If he repents, well and good; otherwise, he is killed. How can he say this?! …… He says: We fight innovations, we fight what Allah has forbidden, what contradicts [the truth]. But as for fighting everything old: the prayer is old, Hajj is old, fasting is old, and zakah is old: [Al-Ma'idah: 2], enjoining good and forbidding evil, all of this is old and was brought by the Messenger of Allah (peace and blessings be upon him). Do we fight this?
Whoever says that this is fought against is a disbeliever and an apostate according to all scholars. Or if he says that some of it is fought against, even if he says that Hajj alone is fought against, just Hajj alone, or fasting alone; that is disbelief. It is not all of what the Messenger of Allah (peace and blessings be upon him) brought. If he says that one of these is fought against and is not prescribed for it; that is disbelief …… Is tawhid, prayer, fasting, Hajj, and jihad all fought against? Meaning: he does not submit except to what they have innovated, what the Jews and Christians have innovated, or …… or the communists.
The point is that the Modernists, according to what I have learned about them, are wicked atheists. They must be fought against, and they must be called to repent. If they repent, well and good; otherwise, they are killed, except for whoever displays his repentance, then praise be to Allah.