How would you properly express this sentences?

Have the heroes gone away in the modern world? And who is can called a hero at all?
I think that heroes existed and will exist forever
There are extraordinary people in every society and they commit extraordinary acts. We call them heroes.. Heroes are role models.

The hero is a person who commits act of self-sacrifice to achieving an overarching good..
Some people believe that a hero has to be the military. And his heroic deeds, must necessarily be associated weather acts of war, or battles, or battles
Of course, every point of view has the right to exist
However some people believe that to help an old lady across the street - this is a great deed to do.
Some people believe that every person who lives - is a hero just because he lives and sometimes doing something good for someone else
I think just need to draw the line between heroism and nobility. For example to save a drowning man in a river - is a noble thing to do.
And covering oneself back other people from the bullets of terrorists, it is heroism.
Heroes are people who save other people (from fire, from drowning), etc
To be a hero it implies to be tribute not only to accept - is to the advantage of carry the duty of protection and assistance, the obligation doing good deeds