In latin a group of four is quadri -
quadrigae : four-horse team.
Quadrivium: place where four roads meet, crossroads,
Quadriangulus: four angles
Quadriennium; four years
Quadriduum: four days
Cohort , legion or maniple .
One group would be called the Zealots.
decemvir
medieval religoin
trio
Quartet.
The Evangelicals might be the group you're looking for.
A Roman military group that consisted of about 6000 soldiers was called a legion.
Catholicism is the largest religious group in Canada.
A group of trees is called a wood from which a forest area could be called a woodland.
A group of five is called a "Quintet".
The group or flock of people who obey and respect the catholic priests are 'Roman Catholics.'