The Pilgrim's Progress from This World to That Which Is to Come is a Christian allegory written by John Bunyan and published in February, 1678. It is regarded as one of the most significant works of religious English literature, has been translated into more than 200 languages, and has never been out of print. The author says in the preface " I have endeavored as far as possible to avoid hard and technical expressions, and I cannot but think that the mere fact of the brevity of the words must be a great attraction to beginners of all ages. (Summary by Wikipedia and the preface)