Christianity is the predominant religion in Europe. Christianity has been practiced in Europe since the first century, and a number of the Pauline Epistles were addressed to Christians living in Greece, as well as other parts of the Roman Empire.
According to a 2010 study by the Pew Research Center, 76.2% of the European population identified themselves as Christians.
Criticism of Christianity has a long history that stretches back to the initial formation of the religion in the Roman Empire. Critics have challenged Christian beliefs and teachings, as well as actions taken in the name of the faith, from the Crusades to modern terrorism. The arguments against Christianity include claims that it is a faith of violence, corruption, superstition, polytheism, homophobia, bigotry, pontification, abuses of women's rights, and sectarianism.
In the early years of Christianity, the Neoplatonic philosopher Porphyry emerged as one of the major critics with his book Against the Christians, along with other writers like Celsus and Julian. Porphyry argued that Christianity was based on false prophecies that had not yet materialized. Following the adoption of Christianity by the Roman Empire, dissenting religious voices were gradually suppressed by both governmental and ecclesiastical authorities. Christianity has faced significant theological criticism from thinkers of other Abrahamic religions, particularly including Judaism and Islam. Notably, Maimonides, the renowned rabbi, Jewish philosopher, and Torah scholar of the 12th century, argued that Christian practices and doctrines constituted idolatry and deviated from the strict monotheism (shituf) of Jewish and Muslim theologies. Similarly, Islamic scholars have critiqued Christian beliefs about the Trinity and the divinity of Jesus, viewing these concepts as incompatible with the concept of monotheism. These critiques reflect deep theological disagreements rooted in their shared scriptural traditions and divergent doctrinal interpretations. A millennium later, the Protestant Reformation led to a fundamental split in European Christianity and rekindled critical voices about the Christian faith, both internally and externally. In the 18th century, deist philosophers such as Voltaire and Jean-Jacques Rousseau were critical of Christianity as a revealed religion. With the Age of Enlightenment, Christianity was criticized by major thinkers and philosophers, such as David Hume, Thomas Paine, and the Baron d'Holbach. The central theme of these critiques sought to negate the historical accuracy of the Christian Bible and focused on the perceived corruption of Christian religious authorities. Other thinkers, like Immanuel Kant, offered critiques of traditional arguments for the existence of God, while professing to defend Christian theology on novel grounds.