What is the correct understanding of the concept of extremism and extremists?

Question:
There has been much talk about extremism and extremists, and opinions have differed regarding the concept of extremism. Academic integrity requires resolving this issue, knowing that Your Eminence is one of those by whom disagreement is resolved in this era, and praise be to Allah?

Answer:
Extremism and extremists: many of the enemies of the Islamic call have adopted this as a cover to destroy the call and its people, and to prevent the manifestation of the Islamic call. They say: "Extremism" and "extremists." Sometimes they say: "They are communists," and sometimes they say otherwise; to justify to themselves their prevention of them and their taking action against them.
Sometimes, by "extremist" and "extremism" is meant: strictness in religion, innovations, and dissatisfaction with what Allah and His Messenger and our righteous predecessors accepted in terms of justice and moderation in matters. This is correct if the innovator and the strict one who contradicted the Shari'ah is called an extremist; this is correct.
But the majority of those who use the term "extremism"—the majority of these people—mean: the active one in calling to Allah, the one with zeal for Allah, the one eager to establish the religion of Allah. They call him an extremist, and they call his speech extremism; to prevent him, or to make people averse to him.
So whoever calls to what Allah has made obligatory, and to leaving what Allah has forbidden, and adheres to Allah without addition; he is not an extremist. The one who says to people: "Pray, O people, in congregation. Leave riba (usury or interest). Beware of riba. Maintain your family ties. Be dutiful to your parents. Let the beard grow. Do not let your garments hang below the ankles. Do not let your clothes hang below the ankles"; all of this is not extremism. This is a caller to what Allah and His Messenger called to. But those who persist in these sins call him an extremist, so that they may make people averse to him, so that they do not accept from him. And he is a guide, guided in this, successful. But Satan makes those sinners averse to him, and He puts on their tongues words that make people averse to extremism and extremists.
And some states claiming affiliation with Islam do this with the callers to truth, and with the callers to tawhid (the oneness of Allah). They say: "Extremists." Sometimes they say: "Communists." To justify to themselves destroying them, imprisoning them, torturing them, and harming them because they are extremists, or because they are communists. And they are liars. They are not extremists, and they are not communists. But they said to them: "Rule by the law of Allah. Fear Allah. Leave what Allah has forbidden. Prevent zina (unlawful sexual intercourse) and khamr (intoxicants)," and so on of what the callers to truth say. So the one who does not want that and is not satisfied except with laws says: "These are extremists."
This and its like is the distinction between extremism and non-extremism:
The extremist is the one who calls to innovations and additions in religion.
And the harsh one is the one who commits sins and calls to them.
And the moderate one is the one who commands what Allah and His Messenger commanded, and forbids what Allah and His Messenger forbade. If he is called an extremist, it is an aggression against him, and he is not an extremist. And Allah is the One sought for help.