Why are cults and sect called new religious movements?

Sect and cults are sociological terms that describe groups
that have broken away from the main religious group. Sects and cults, therefore, are no
longer within that group. In other words, the main group wishes to distance themselves
from the sect or cult. They see incompatibility. In essence they see something new.
Sects and cults are fully aware of this fact and they, too, seem themselves as
different.

Since, there is this distancing, they are
called new religious movements. Sometimes, cults and sects try to reform the main
religion and they fail to do so. So, they leave. Other times, there is a charismatic
leader who rouses people to follow him or her and a group leaves. In all, the basic
point is that something new is created. So, sociologists call them sects and cults.