Christianity is an Abrahamic, monotheistic religion based on the life and teachings of Jesus of Nazareth, known as Christ. Its name is derived from the title “Christ,” meaning 'anointed one' in Greek. Followers, known as Christians, believe Jesus is the Son of God and the savior of humanity, whose coming was prophesied in the Old Testament.

Originating in the 1st century AD as a sect within Second Temple Judaism in Roman-occupied Judea, Christianity quickly diverged from Judaism, particularly after the destruction of the Second Temple in 70 AD. It spread throughout the Roman Empire and beyond, evolving into a distinct religion. Christianity was legalized in the Roman Empire by Emperor Constantine's Edict of Milan in 313 AD and later became the state religion in 380 AD.

An Eastern Christian icon depicting Emperor Constantine and the Fathers of the First Council of Nicaea in 325 as holding the Niceno–Constantinopolitan Creed of 381.

Central to Christian doctrine is the belief in Jesus as the incarnate Son of God, who died on the cross and rose from the dead for the salvation of mankind—a message encapsulated in the New Testament. The Bible, comprising the Old and New Testaments, is considered the sacred scripture. Christians believe in the Trinity—Father, Son, and Holy Spirit—as one God in three persons.

Catholic Church: Emphasizes papal authority and church tradition.

Orthodox Christianity: Includes the Eastern Orthodox and Oriental Orthodox Churches, stressing adherence to inherited traditions and liturgies.

Protestantism: Characterized by the rejection of papal authority and a focus on the Bible as the sole source of divine truth. Major reform movements include Lutheranism, Calvinism, Anglicanism, and Methodism.

Restorationist and Non-traditional Groups: Such as Mormons, Jehovah's Witnesses, and Christian Scientists, which often differ significantly in doctrine from mainstream Christianity.

Christianity has profoundly influenced Western civilization and continues to play a significant role in global affairs. Today, it is the world's largest religion with approximately 2.38 billion adherents across diverse cultures and societies. Despite its historical dominance in the West, Christianity is experiencing growth in Africa and Asia, while facing challenges such as secularization in the West and persecution in various regions.

Efforts toward ecumenism seek to promote unity among Christian denominations. Additionally, interfaith dialogue between Christians and followers of other religions aims to foster mutual respect and understanding.

Christianity has been a driving force in the arts, science, philosophy, and politics. It has inspired some of the world's greatest artworks, contributed to the establishment of universities and hospitals, and played a key role in the development and spread of values such as human rights and social justice.