Søren Aabye Kierkegaard (May 5, 1813–November 11, 1855) was a Danish philosopher, theologian, and preacher, widely regarded as the father of existentialism, whose writings profoundly influenced Christian thought and modern philosophy. Born in Copenhagen to Michael Pedersen Kierkegaard, a wealthy merchant with a strict Pietist faith, and Ane Sørensdatter Lund, his father’s former servant, Søren was the youngest of seven children, though only he and his brother Peter survived to adulthood. Raised in a melancholic household shaped by his father’s guilt over a youthful curse against God, he studied theology at the University of Copenhagen, earning a Magister Artium in 1840. His life took a pivotal turn after he ended his engagement to Regine Olsen in 1841, a decision that fueled his introspective and spiritual writings. Though not an ordained pastor, Kierkegaard preached through his literary works and occasional sermons, such as those at Copenhagen’s Trinitatis Kirke, emphasizing a radical, personal faith over institutional religion. His books, including Fear and Trembling (1843), The Sickness Unto Death (1849), and Practice in Christianity (1850)—often penned under pseudonyms like Johannes Climacus—critiqued the Danish State Church’s formalism, advocating a "leap of faith" to embrace authentic Christianity. In his final years, he launched a public attack on the church via The Moment pamphlets (1855), accusing it of diluting Christ’s call. Unmarried and childless, he died in Copenhagen in 1855 from a spinal condition, leaving a legacy as a preacher of existential truth and spiritual urgency.