This crucial entry in Christian mythology was written in 1678 and is probably most familiar to modern readers as a book read by Alcott's Little Women. Bunyan's story is an unapologetic allegory; his main character, Christian, leaves his wordly life and goes on a pilgrimage to the Holy City, encountering plainly named obstacles and object lessons along the way. He must avoid the Giant Despair; walk through the Valley of Darkness; discourse with fellow pilgrims Ignorance, Faithful, Atheist, and Pliable, etc., etc. I can see why the book has been so enduringly popular; the style is charming and plain, and lends itself easily to being read aloud. The archaic language might give readers pause, but in audio-book format it was very easy to understand.
The Pilgrim's Progress has contributed some proverbs and turns of phrase to our language: Christian is told to stick to 'the straight and narrow'; one of his first obstacles is the Slough of Despond; and he passes through the town of Vanity Fair.
I can't really say I enjoyed it (well, I'm not Christian, am I?) but it was a fascinating look at the bedrock of Christian belief; that one must utterly abandon the world to reach salvation. Rather an unusual idea these days. And I've always wanted to read it just for the cultural significance. I count this one as time well spent.