Søren Kierkegaard (1813–1855) was an outstanding Danish philosopher, theologian and writer, the founder of existentialism. What is existence? What does it mean to exist? In search of answers to these questions, Kierkegaard raised a whole layer of problems that inevitably confront a thinking person. Despair, fear, self-deception, desire for sin, repentance, torment of choice - he wrote only about what he deeply felt from his own experience. Kierkegaard boldly polemicized with official theology, defending the thesis about the reality of Christianity only for the elite. His work had a huge influence on the literature, philosophy and theology of the twentieth century and remains relevant to this day.