The concept of religion in the Western world has developed through a long historical process shaped by philosophy, theology, political change, scientific advancement, and social transformation. In Western intellectual traditions, religion is commonly understood as a system of beliefs, practices, moral values, and institutional structures centered on the relationship between human beings and a transcendent or supernatural reality. This understanding has been influenced strongly by Christianity, particularly in Europe and later in North America, where Christian frameworks shaped definitions, social roles, and institutional expressions of religion. Over time, however, the Western concept of religion has expanded and diversified, especially through encounters with other cultures, the rise of secularism, and the growth of comparative studies of religion. In early Western thought, particularly in ancient Greece and Rome, religion was not clearly separated from civic life. Religious practices were embedded in public rituals, festivals, and state functions. The emphasis was not primarily on personal belief but on participation in communal worship and maintaining harmony between society and the divine. With the rise of Christianity in the Roman Empire, religion became increasingly centered on faith in one God, doctrinal belief, and moral conduct. Christianity introduced a strong emphasis on inner conviction, salvation, and personal relationship with God. This shift contributed significantly to the Western understanding of religion as a matter of belief as well as practice. During the medieval period, religion in the West became closely associated with institutional authority, particularly the Church. The Church played a central role in education, governance, moral regulation, and social organization. Religion was not considered a separate sphere of life; instead, it permeated political and cultural institutions. The unity between religious and social order reinforced the idea that religion provided ultimate meaning, moral guidance, and legitimacy to authority. The theological worldview dominated intellectual life, and religious explanations were widely accepted as authoritative. The Renaissance and the Reformation brought significant changes to the Western understanding of religion. The Protestant Reformation, in particular, emphasized individual interpretation of sacred texts, personal faith, and direct relationship with God without dependence on centralized ecclesiastical authority. This movement contributed to the development of religious pluralism within Christianity itself and strengthened the role of individual conscience. Religion began to be associated more strongly with personal belief and inner conviction rather than solely institutional belonging. These changes laid the foundation for modern conceptions of religion in the West. The Enlightenment further transformed the concept of religion. Enlightenment thinkers emphasized reason, scientific inquiry, and critical thinking. Religion was increasingly examined through rational analysis rather than accepted unquestioningly. Some philosophers criticized organized religion, while others sought to reconcile faith and reason. During