Søren Kierkegaard

"Danish philosopher, theologian, and cultural critic who was a major influence on existentialism and Protestant theology in the 20th century. He attacked the literary, philosophical, and ecclesiastical establishments of his day for misrepresenting the highest task of human existence—namely, becoming oneself in an ethical and religious sense—as something so easy that it could seem already accomplished even when it had not even been undertaken. Positively, the heart of his work lay in the infinite requirement and strenuous difficulty of religious existence in general and Christian faith in particular." Source: Britannica