This book has more than once been characterized as “the theological bestseller of the 20th century.” Its readers saw in it, first of all, the substantiation of a certain non-confessional mystical doctrine. However, it would be a clear mistake to reduce Otto’s position to mysticism. He specifically stipulates that the irrational and rational are inextricably linked in religion. The book had a huge influence on religious studies of the 20th century, laying the foundation for the phenomenology of religion. Although Rudolf Otto himself wrote that this book was born during seminars with theological students out of the need to explain to them what the sin of wine is, what is the meaning of “atonement for sins” in Christianity.