Catholic and Protestant Christian groups fight in Northern Ireland different Muslim sects are in conflict in Lebanon, Iran-Iraq. Christians and Muslims are in conflict in Egypt as the Pope travels in Egypt. There are Buddhist and Hindu conflicts in Sri Lanka. Unlike language, which is an attribute of all people, Religion varies in its role in culture. Religion dominates some cultures and is less important in others.
All societies have value systems that direct how one acts and interacts in society.
That value system is called a religion when it involves a system of formal or informal worship and faith in the sacred or divine. Religion may intimately affect all aspects of a culture and intimately affect the worldview of a culture. Economic patterns can be intertwined with religion. Certain restrictions are placed on food and that affects the type of plants grown and type of animals raised or avoided. The imprint of religion on the landscape is both obvious and subtle.