I would expect there are more than three. These three could get us started.
ZarathUshtra (circ 4000bce) was opposed to slavery, even to the gods. It was the Magians and Achæmenids who resurrected the gods and enslaved the world in the name of the newly reborn Zoroastrian gods.
Buddhism and Jainism (600 bce), and their youngest brother, Sikhism (15th century ce) oppose slavery for the same reason ZarathUshtra taught against it. One ought to be responsible for one's own enlightenment. And slaves aren't allowed to be responsible for themselves, nor even have their own thoughts.
The Bogomils / Cathar (9th to 12th century ce) gnostics opposed slavery, even teaching trade and self-reliance as the path out of oppression and onto enlightenment.
Quakers: Quakers were one of the first religious groups to actively oppose slavery and played a significant role in abolitionist movements.
Unitarians: Unitarians believed in the inherent worth of all individuals and opposed slavery on moral grounds.
Methodists: Methodists in the United States became increasingly vocal in their opposition to slavery, leading to the split of the denomination into Northern and Southern branches over the issue.
During the Crusades, three major religious groups were fighting over control of Jerusalem and the Holy Land. Muslims, Christians, and Jews all had significant interests in the region, leading to centuries of conflict and political instability. Jerusalem was considered a holy city by all three groups, making it a central focus of the Crusades.
The three major religious groups in Bosnia are Bosniaks (Muslims), Serbs (Orthodox Christians), and Croats (Catholics). Bosniaks adhere to Islam, Serbs are Orthodox Christian, and Croats are predominantly Catholic. These religious differences have historical and cultural significance in addition to shaping individual identities and communal relations in Bosnia.
The three main religious groups in the Middle East are Islam, Christianity, and Judaism. Islam is the largest religion in the region, followed by Christianity and Judaism. Each of these religions has deep historical and cultural roots in the Middle East.
Three non-religious holidays are Independence Day, Valentine's Day, and Thanksgiving. These holidays are not tied to any specific religious beliefs and are celebrated by people of diverse backgrounds and cultures.
The three colonies settled for religious reasons are Massachusetts (Pilgrims and Puritans seeking religious freedom), Pennsylvania (Quakers seeking religious tolerance), and Maryland (Catholics seeking refuge from persecution).
First tell us WHICH war. Then we can answer which 3 groups.
Religious groups, advocacy groups, and the media.
Reform (Least Religious) Conservative (More Religious) Orthodox (Most Religious)
The three religious groups that were in conflict in the Balkans were Islam, Orthodox Christianity, and Roman Catholicism. Each of the religions was fighting for dominance and control of the region.
POOP
West Virginia, East Tennessee, Ozark Mountains
During the 1858 Lincoln Douglas debates, Senator Douglas named three groups that opposed the Fugitive Slave Act. The first group opposed the act totally. They refused to comply with it. The second group opposed the act but recognized it as law. The third group opposed the act but recognized it was needed for the 1850 compromise.
There are no religions groups that focus on tai chi. It is a martial art, not a religion.
Churches, unions, and corporations. Hope this helped(:
islam, chistianity, judaism
the Pharisees, the Sadducees, and the Essenes
I think they are the Shia Sunni and Kurds or possibly Sufi